I noticed that clicking multiple times on one these tabs which is not selected adds up the loading GIF (in the profile page):
Here is an image of it happening:
Its hard to explain whats happening so here is a GIF:
This behavior is noticed by me in all SE sites.
Try it yourself. Open any profile (with some posts) on any network, and start clicking.
Produced on Chrome V76 - Windows 10 (64 bit)
This can also be reproduced with other dialogs and tabs which involve the GIF loading. I reproduced it with the close, & flag question dialog as well.