Why can't I see all pics?

[BINOVC]

I can see some pics, but not all.
Example I don't see Gobux's "Bike leaning on kickstand" pic, but I assume there must be one.
In same post I see klb's pic, and MarkT's pics.
This happens in many posts, and on different computers.  Using different browsers doesn't change anything, except in IE there's a small square with X in it where the pic is, Chrome doesn't even show that.
Any ideas?

[WintrSol]

Perhaps because Gobux's pic is hosted on a different site? (postimage.org)

[gordonv]

Is there an img or a box where the picture should be, or nothing?

I get some posts where there is nothing, and others are talking about the pictures that they see. I forget the outcome. But I believe the question was and should be in the general forum posts, rather than the Tech section.