Currently in the Thumbnails Pane on Revu, there's an option to show Page Label and Page Scale beneath each page's thumbnail. There's also a helpful "Create Page Labels" button which works best in documents where all the pages are the same size.
When documents contain multiple page sizes, it slows down the process of using the "Create Page Labels" tool to grab a page number or sheet title, since that text often moves depending on page size. Being able to show page sizes in the thumbnail view would allow users to only select sheets of one size at a time without having to guess whether the tool works based on thumbnails.
Showing page size would also help users select only pages of a certain size when printing, (e.g. to large format printers.)