Using stegdetect, which gives me an "approximate" result – there can probably be false positive.
The file I mentioned however (hashed filename)
d879e4fd98e8922c194bd9a50f6ea4e5fa6da7a68331269372ba76714aa61b12.jpg
from post
07-Jan-2018 22:03:47
definitely has stuff in there, and it appears non-encrypted, since I could see the PK signature and contained filename.
So actually anyone can have a look at the file and give it a try.
Original filename (in the mentioned post) was "Inkedq_LI.jpg"