@dawgofdawgness If you see it instead people's avatars, forum interface pictures, or recent pictures, uploaded by users, than it seems like your browser issues, or poor internet connection, which prevent images from being loaded correctly.
But if you see it only in old threads on place of pictures, which people have left in them, it may mean that these pictures were uploaded on third-party hosting, their storage time was expired and they were deleted from hosting. I.e. that they objectively don't exist (at provided link adress) anymore and that's why can't be shown on this forum either.