Small filesize thumbnail ignored

Hi all.

For some reason I can’t get the following image file to appear as a thumbnail and also it doesn’t show a preview when browsing the screenshots folder.

I checked names and everything is set right, the only idea I have that it’s under 2 kb. Any clues as to why this happens?

PS.: Tested on Windows, Linux and Lakka RPi, same behavior.

-180102-130330