I love the idea of a video wall, or a sheet as you call it. You get a quick overview of your movies or series and can pretty much select one of your interest, just by looking at the covers.
The problem however is that much of this covers is hidden or cut off, to allow several items in a perfect square setup on this "wall". The covers that you need to make up your mind is badly crippled, and in some cases even the title is missing. This makes using this video wall much less useful than it should be.
A bug is also introduced because of this clipping of the covers. When you enter the Large info view after looking at a DVD/Bluray cover or a thumbnail, you'll end up with the crippeled cover in the Large info view. I do not think this is intended.
I want to suggest that you make the shape of the media art depending on what is shown or what level you are on. What about something like this?
- Audio: Keep the Square shape for album art
- Video: Use High rectangle shape (video covers) for Movies and Series art (season later on hopefully). Change to horizontal rectangle shape when browsing with thumbnails on the bottom level.
- Mixed: If there is users mixing this media types, I would suggest that you perhaps keep this Square shape, so it looks better if there is both albums, thumbnails and covers present.
I hope you will find the time to look at this soon.