We have been receiving a lot of submissions lately with either a very small preview, or no preview at all. When submitting anything to a gallery in WinCustomize you must have a correctly sized preview or the submission will be rejected.
You can find more info in the
Tips for Moderation Guide.
Wallpaper, .dream, WindowBlinds, Logons, etc. submissions need to have a preview of at least 1024x768.
CursorFX, Icons, etc. can have a smaller preview, but I would recommend at least a 400px preview at the minimum.
Thanks!