Viewing two separate images is very different from adding full DAM features to DxO PhotoLab. It would be tremendously useful to be able to see two different shots at the same time. Even this gets complicated though - what settings would be applied? Can both images have their settings changed in real time?
In that case, it’s really two instances of DxO at the same time.
When I think about how much trouble this feature would bring, I go back to John’s POV on this issue:
Note : It is possible, of course, to move back-and-forwards between 2 images in PL’s Full-Screen Viewer - - but that’s never fast enough on my environment for critical analysis of two images. For this purpose, I use a dedicated image-viewer application … such as Irfan (excellent & free) or Fast Raw Viewer (excellent but not free).
The time to choose between two images is before DxO Photo Lab.
I have added some additional notes on image comparison software on Mac at the related feature request. We should probably keep that part of the conversation over there.