The only way I can think of is actually outside Profiler.
The smaller images are very likely to be much smaller in size than the hi-res scans in terms of kb.
So if you browse to your images folder in Windows Explorer and sort by file size, you should see all the smaller images grouped together.
Unfortunately the only way to identify them would be either visually recognising the cover or taking the UPC from the filename.

I'll just start opening up the fullsize pictures in my local, then right-click the big picture in the middle and click the "stretch to fit" option. Most shrink a tiny bit (think I have my window set a little bigger than default) and I'll know they're the right size. Even the ones I put in will show huge, like a zoom in, if not approved, but will be standard size if they were accepted. Then if there's issues of any sort, I'll scan mine and submit. Of course this takes a lot more time so I'll just do a letter or 2 per sitting.
Unfortunatly I broke my extra scanner glass the other day, so I'm out of the scanning business for a bit. A tip to other would-be scanners. Take a sheet of glass from a picture frame to get your covers to lay nice and flat by placing over the cover on the scanner glass. This will cut out glare on the edges and just make better scans all around. Even with the frame-glass you might have to hold it all down by hand. Always turn out the lights if you have to leave scanner cover open to hold covers down flat, or else the colors and brightness get off and glare still happens. I have to do this as my bed is slightly deeper than the frame-glass, and the cover alone doesn't hold it flat.

What the others said about sorting by dimension...
And if you're still looking to make work for yourself,    also sort by size and make note of those images significantly smaller than 195KB.  Since Ken changed the maximum file size to 200,000 bytes, there's a good possibility that many you'll find are overcompressed and lousy with artifacts - especially covers with a lot of fine detail or red content. Another opportunity to improve even when the current dimensions are correct.