I do not use WinMerge, although many like it ... I prefer Beyond Compare as I can do an FTP compare from my computer to the server ...
I can select the default template and compare to a custom template etc. by just pointing at the directories to compare to one another ...
Another method is the Developers Tool Kit ... do a search on:
Additional Product Images
and see what files come up and that should give you a lead to what files to start looking at ...



