You can upload several files in a row, selecting all of them from the window opened by clicking the Select files button. After selecting them, you need to click the Upload Files button.
If you've selected some image files (png, jpg or gif), the first three images uploaded will be downloaded and shown down the page.
After cloning the repo, you can start the app by:
$ npm install
$ npm run start
If you want to modify the code while testing it, you can start the app with the nodemon
module:
$ npm run devstart
Open on a browser http://localhost:3000 to start ussing the app.