Update readmes, plugin URIs, and descriptions

plugins/image-prioritizer/load.php

@@ -1,8 +1,8 @@
 <?php
 /**
  * Plugin Name: Image Prioritizer
- * Plugin URI: https://github.com/WordPress/performance/issues/1088
- * Description: Optimizes the loading of the LCP image by leveraging client-side detection with real user metrics.
+ * Plugin URI: https://github.com/WordPress/performance/tree/trunk/plugins/image-prioritizer
+ * Description: Optimizes LCP image loading with fetchpriority=high and applies image lazy-loading by leveraging client-side detection with real user metrics.
  * Requires at least: 6.4
  * Requires PHP: 7.2
  * Requires Plugins: optimization-detective

plugins/image-prioritizer/readme.txt

@@ -9,15 +9,24 @@ License:           GPLv2 or later
 License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 Tags:              performance, images
 
-Optimizes the loading of the LCP image by leveraging client-side detection with real user metrics.
+Optimizes LCP image loading with fetchpriority=high and applies image lazy-loading by leveraging client-side detection with real user metrics.
 
 == Description ==
 
-Optimizes the loading of the LCP image by leveraging client-side detection with real user metrics. Currently, this involves adding `fetchpriority=high` to the LCP image and adding preload links for the LCP `img` as well as any LCP `background-image`.
+This plugin optimizes the loading of images which are the LCP (Largest Contentful Paint) element, including both `img` elements and elements with CSS background images (where there is a `style` attribute with an `background-image` property). Different breakpoints in a theme's responsive design may result in differing elements being the LCP element. Therefore, the LCP element for each breakpoint is captured so that high-fetchpriority preload links with media queries are added which prioritize loading the LCP image specific to the viewport of the visitor.
 
-This plugin requires the [Optimization Detective](https://wordpress.org/plugins/optimization-detective/) plugin as a dependency.
+In addition to prioritizing the loading of the LCP image, this plugin also optimizes image loading by ensuring that `loading=lazy` is omitted from any image that appears in the initial viewport for any of the breakpoints, which by default include:
 
-TODO: Flesh out description.
+1. 0-320 (small smartphone)
+2. 321-480 (normal smartphone)
+3. 481-576 (phablets)
+4. >576 (desktop)
+
+If an image does not appear in the initial viewport for any of these viewport groups, then `loading=lazy` is added to the `img` element. 
+
+Note that by default, URL Metrics are not gathered for administrator users, since they are not normal site visitors, and it is likely that additional elements will be present on the page which are not also shown to non-administrators.
+
+This plugin requires the [Optimization Detective](https://wordpress.org/plugins/optimization-detective/) plugin as a dependency. Please refer to that plugin for additional background on how this plugin works as well as additional developer options. 
 
 == Installation ==
 

plugins/optimization-detective/load.php

@@ -1,8 +1,8 @@
 <?php
 /**
  * Plugin Name: Optimization Detective
- * Plugin URI: https://github.com/WordPress/performance/issues/869
- * Description: Uses real user metrics to improve heuristics WordPress applies on the frontend to improve image loading priority.
+ * Plugin URI: https://github.com/WordPress/performance/tree/trunk/plugins/optimization-detective
+ * Description: Provides an API for leveraging real user metrics to detect optimizations to apply on the frontend to improve page performance.
  * Requires at least: 6.4
  * Requires PHP: 7.2
  * Version: 0.3.0

plugins/optimization-detective/readme.txt

@@ -9,11 +9,11 @@ License:           GPLv2 or later
 License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 Tags:              performance
 
-Provides an API for leveraging real user metrics to improve the heuristics WordPress applies on the frontend to optimize page performance.
+Provides an API for leveraging real user metrics to detect optimizations to apply on the frontend to improve page performance.
 
 == Description ==
 
-This plugin captures real user metrics about what elements are displayed on the page across a variety of device form factors (e.g. desktop, tablet, and phone) in order to apply loading optimizations which are not possible with WordPress’s current server-side heuristics. This plugin is a dependency which does not provide end-user functionality on its own. For that, please install the dependent plugin [Image Prioritizer](https://wordpress.org/plugins/image-prioritizer/) (among others to come from the WordPress Core Performance team).
+This plugin captures real user metrics about what elements are displayed on the page across a variety of device form factors (e.g. desktop, tablet, and phone) in order to apply loading optimizations which are not possible with WordPress’s current server-side heuristics. This plugin is a dependency which does not provide end-user functionality on its own. For that, please install the dependent plugin [Image Prioritizer](https://wordpress.org/plugins/image-prioritizer/) (among [others](https://github.com/WordPress/performance/labels/%5BPlugin%5D%20Optimization%20Detective) to come from the WordPress Core Performance team).
 
 = Background =
 
@@ -23,7 +23,7 @@ In order to increase the accuracy of identifying the LCP element, including acro
 
 = Technical Foundation =
 
-At the core of Optimization Detective is the “URL Metric”, information about a page according to how it was loaded by a client with a specific viewport width. This includes which elements were visible in the initial viewport and which one was the LCP element. Each URL on a site can have an associated set of these URL Metrics (stored in a custom post type) which are gathered from real users. It gathers a sample of URL Metrics according to common responsive breakpoints (e.g. mobile, tablet, and desktop). When no more URL Metrics are needed for a URL due to the sample size being obtained for the breakpoints, it discontinues serving the JavaScript to gather the metrics (leveraging the [web-vitals.js](https://github.com/GoogleChrome/web-vitals) library). With the URL Metrics in hand, the output-buffered page is sent through the HTML Tag Processor and the images which were the LCP element for various breakpoints will get prioritized with high-priority preload links (along with `fetchpriority=high` on the actual `img` tag when it is the common LCP element across all breakpoints). LCP elements with background images added via inline `background-image` styles are also prioritized with preload links.
+At the core of Optimization Detective is the “URL Metric”, information about a page according to how it was loaded by a client with a specific viewport width. This includes which elements were visible in the initial viewport and which one was the LCP element. Each URL on a site can have an associated set of these URL Metrics (stored in a custom post type) which are gathered from real users. It gathers a sample of URL Metrics according to common responsive breakpoints (e.g. mobile, tablet, and desktop). When no more URL Metrics are needed for a URL due to the sample size being obtained for the breakpoints, it discontinues serving the JavaScript to gather the metrics (leveraging the [web-vitals.js](https://github.com/GoogleChrome/web-vitals) library). With the URL Metrics in hand, the output-buffered page is sent through the HTML Tag Processor and--when the [Image Prioritizer](https://wordpress.org/plugins/image-prioritizer/) dependent plugin is installed--the images which were the LCP element for various breakpoints will get prioritized with high-priority preload links (along with `fetchpriority=high` on the actual `img` tag when it is the common LCP element across all breakpoints). LCP elements with background images added via inline `background-image` styles are also prioritized with preload links.
 
 URL Metrics have a “freshness TTL” after which they will be stale and the JavaScript will be served again to start gathering metrics again to ensure that the right elements continue to get their loading prioritized. When a URL Metrics custom post type hasn't been touched in a while, it is automatically garbage-collected.