This video is just your basic unboxing video. I purchased my box on eBay. Currently the prices are actually kind of high because of a change in one of the cards, so I think there was a recall or something?
To listen while using other apps, switch the player to Picture-in-Picture (PiP) during playback — it keeps playing in a small floating window (the screen stays on).
To listen with the screen fully off, in-browser playback stops by YouTube's design. Open the video in the YouTube app to keep listening where background playback is supported (e.g. with YouTube Premium).
Open in YouTube app