Images in PMs showing as from 'my' gallery

And these are from other members' PMs to me.

Windows 10, Firefox 68.0b12 X64
EDIT: now on Firefox 72.0b3 X64, same result

So far, the images are hosted here on the POTN server.
I can only be certain they're from one member so far.

I get this at bottom of an image when viewing within a PM:

(ID in parentheses obfuscated in case sender doesn't want it public;
crop shows fraction of image/page)

I have only one image in my gallery(shameful, I know), so I know this is not
part of my own gallery. I've received a few Flickr and other off-site IMG tags
within PMs before, and I don't recall seeing this on those occasions.

Craig5D4|50D|S3iS|AF:Canon 28-135 USM IS|MF:Tamron SP 28-80|Tamron SP 60-300|Soligor 75-260|Soligor 400|Soligor C/D 500|Zuiko 50 f/1.8|others
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Wild Birds of Europe: https://photography-on-the.net …showthread.php?​p=19371752
Please QUOTE the comment to which you are responding!

Craig5D4|50D|S3iS|AF:Canon 28-135 USM IS|MF:Tamron SP 28-80|Tamron SP 60-300|Soligor 75-260|Soligor 400|Soligor C/D 500|Zuiko 50 f/1.8|others
Support this exceptional forum
Of course I'm all right! Why? What have you heard?!?