help: User does not need to click on "Show other applications"
If <app>Image Viewer</app> is not on the <gui>Recommended Applications</gui> list,
click <gui>Show other applications</gui>. Select <gui>Image Viewer</gui> from the list
that appears and click <gui>Set as default</gui>.
https://gitlab.gnome.org/GNOME/eog/-/blob/master/help/C/default.page#L42-44
Hotfix:
If <app>Image Viewer</app> is not on the <gui>Recommended Applications</gui> list,
select it from the <gui>Other Applications</gui> list and click <gui>Set as default</gui>.
Edited by Ghost User