How to compare two folders side by side - images view?

Up front: probably a newbie question, but I hardly ever use the 'dual display' feature.

Say I wish to compare the images within 2 different folders.
-Select Dual Display in View
-Select folder 1 in the middle folder list
-Select folder 2 in the right folder list

Now I would like to have thumbnails displayed in both, so as to see where they differ.

I vainly tried to get that done, but then again, maybe it is simply not possible?

Thanks

Click one side to activate it. Click the Thumbnails button on the toolbar.

Click the other side to activate it. Click the Thumbnails button on the toolbar.

If you do it a lot then there are several ways you can automate it, but that's the most general/basic way.

Ah, right.
Many thanks indeed!