thunderbird-31.3.0-1.fc21 does not display photos in messages

[jd1008]

Before I file a bug against TB, I would like to know  what
would cause TB to not display photos in messages. When I view
the same message in Firefox (my gmail account), the photos
are displayed.

What TB does display are squares and rectangles where the photos
ought to be.
Sometime, the rectangles / squares contain the URL of the photo,
other times the content is some text, like ... Amazing or Incredible .. etc.