Pretty sure it's the Rift's ball (Destiny)

by ZackDark , Not behind you. NO! Don't look., Thursday, January 28, 2016, 10:30 (3463 days ago) @ Kahzgul

Which is cool, because it implies we are attacking the Rift.

(The forums don't have HTML open to us per se, so we're limited by the buttons to the right, plus a few hidden tricks. I don't think we can scale pics down, but we can certainly post them as expandable thumbnails when using the button.)