Okay...

I just figured this thing out facepalm

Post # 220211 is in a Forum only accessible to Moderators and Admin.
So, images associated with that post could not be seen by Members or Guests.

But... apparently images linked to posts in accessible forums can be embedded in other posts and in different threads (without uploading) using the img tags

wonder if it would work here too...

[Linked Image from electrical-contractor.net]

ECN Electrical Forum: https://www.electrical-contractor.net/forums/ubbthreads.php
My Day Job: https://www.licensedelectrician.com/