SUMMARY Currently Gwenview offers a wealth of image formats to display - but Krita's .kra files aren't one of them which is a shame considering that both are in the KDE camp and it would be a rather nice way to sort, organize and handle Krita workfiles.
This may be a regression, Gwenview was able to handle .kra files at some point according to these: https://bugs.kde.org/show_bug.cgi?id=337272 https://invent.kde.org/graphics/gwenview/-/commit/5ae28dadba069a56b845c66c6a57f65c3883ede3 However I don't remember .kra files ever working for me in Gwenview though, so can't say for certain.
Could be related to https://invent.kde.org/frameworks/kimageformats/-/merge_requests/17
Thank you for the bug report. Unfortunately we were not able to get to it yet. Can we ask you to please check if this is still an issue with Gwenview 25.08.0 (the latest released version)?