Is there a reason the Japanese Language Icon is 3D sometimes?

Question

This image has both JP stack exchange and meta. Meta displays normally, but the main site became 3D

This image it's just wrong:

Maybe this is due to dark mode in stackoverflow?

Answer 1

Yes, it does appear to be a bug in Stack Overflow's dark mode, as you suggest:

In fact, there is already a post on this topic over on Meta Stack Overflow:

　 https://meta.stackoverflow.com/questions/397173/wrong-icon-showing-up-in-inbox

An employee has already responded over there, and it's currently status-review, so hopefully it'll get sorted out soon :-)