XnView Software

Currently the Export preview shows original and export side-by-side.
Generally the best way to compare two very similar images is not to have them side-by-side, but to have them alternate between the two at the same spot, at some user-determined alternation speed or pause and manually alternate, with a symbol or sound indicating which one is actively showing, as that way the very finest changes are best spotted and understood.
I wonder if there's some way this could happen.
Cheers, David

related
App UI - preview - add preview modes

Cheers, certainly some useful additions there.
Hopefully some of them will get implemented.
For myself alternating original and export is definitely the most useful and perhaps most trivial to implement (compared e.g. to a slider) but I dare say I might find use for all of them as others certainly do.
Whilst there are programs that do do differencing, having it actually in the program itself at the export stage improves workflow massively...