Sleazy Fork is available in English.
Shows just fullsize Image with hotkeys & without pop-ups on many image-hosting sites
added
Thank you for the prompt addition! For me the implementation doesn't work as intended, however. It conflicts with another extension, InformEnter+, and results in the singular display of an icon that the extension adds (to pages with input fields) in place of the intended image. The URL is the internal pointer to the locally stored image of the icon:
moz-extension://bc62cb30-f4be-4e71-932d-a359a58344ec/img/informenter-marker-2.png
In my use of this extension with different image hosts, this is the first time this has occurred, so it's a specific issue with the addition and not a generalized one.
Can't you blacklist pixs.cx website for that extension?
There doesn't seem to be a way to do that for that extension, though I also didn't think of it being a possibility.
Is that the limit of how the conflict can be corrected, then?
You could also ask extension author to change image folder url from /img/ to something else for compatibility, or just look for alternative extension with the same functionality, or just use standard browser means to achieve what it does https://support.mozilla.org/en-US/kb/control-whether-firefox-automatically-fills-forms
Add: pixs.cx
Examples: https://pixs.cx/103qev5evi0m https://pixs.cx/elzzko958vws https://pixs.cx/qypkdkk74jvt https://pixs.cx/wbiev87w6z8n