Having fought hard to keep album thumbnails and have easy switching between them and details it might sound weird coming from me now, but I suggest getting rid of them in favor of tiles in the bottom view.
The way I imagine it would be to have a new "Groups" list stlye that would have tiles instead of album thumbnails. Each tile would have a "files" or "Expand" link on it that would expand the tile to show what is currently called "Details (Grouped)", and on the large thumbnail for each of the groups in this list would be a link called "Tiles" or "Collapse" that would revert to just showing the tiles as thumbnails again.
This would bring the ultimate in convenience for when we are just browsing a long list of cover art in the bottom view, but then want to look at a file inside a specific album.
Perhaps the best reaosn for this change is that it would allow music style browsing in Images and Video views. With music we can use the top view to browse categories and the bottom view to sift through albums. However, in Image and Video views we can only use the "Details" list style in the bottom view if we don't use the [Album] field as part of our organisation method.
Changing to the method I outlined above would allow me, in a Video view of TV shows for example, to have a bunch of [Genre] tiles in the top view and have [Series] tiles in the bottom view. I would theoretically be able to browse genres and series without ever having to double click to go into a specific category. And I would be able to see a list of episodes inside a series at any point by just clicking on the "files" link on the series tile.