While the Collections are now showing up the Android Build of the new Experience, it is missing a “Play” Button, Videos can only be played one by one by manually selecting them.
Since I use these as a “playlist” of some sort, being able to Play the Full Collection in Order.
On what version of the preview are you?
The current version is showing me a big (almost full-width) Watch button at the top of the collection page (just below the backdrop/logo).
Looks like your server may be on 1.41.1 the minimum server version is 1.41.2 for best performance right now with the preview app (it may increase again by release time). That may be why you are seeing those folder icons instead of posters for example and other weirdness