me·ta·phil, der@kobi_lacroix not sure if I understood your use-case right, but a resizable frameless/windowless view is a feature you could find in e.g. #Nomacs image viewer
https://alternativeto.net/software/nomacs/about/
It's #floss and available for win+gnu/linux. In addition, you might wanna check out #qview and #qimgview
