What is meta?
- Any Stack Exchange user can ask a question
- The community provides support, votes on ideas, and reports bugs
- Your voice helps shape the way Stack Exchange operates
I'll venture the guess that this image is generated then cached (as with the Flair, for instance), and will update in time, when the cache is invalidated. If this is so, this answer describes the wait-time (for Flair):
There are also other references to an approximate 24hr wait-time.