It will take a few weeks before I can see if this is still a problem in the most recent version of Gwibber. But if the code for retrieving the contact pictures hasn't been altered, then this is still a problem with Facebook contacts. Twitter avatars are updated as far as I can tell, but Facebook avatars would stay the same after the first time the person's picture is downloaded. Perhaps a condition to check for new pictures once Gwibber starts could fix this problem.
It will take a few weeks before I can see if this is still a problem in the most recent version of Gwibber. But if the code for retrieving the contact pictures hasn't been altered, then this is still a problem with Facebook contacts. Twitter avatars are updated as far as I can tell, but Facebook avatars would stay the same after the first time the person's picture is downloaded. Perhaps a condition to check for new pictures once Gwibber starts could fix this problem.