What is causing this alien icon on fb?

[Amanda]

In the last few months, I've noticed this icon at the end of comments on fb posts. It not on the actual posted comment. Its only under the notifications section. It's only on a select few people and Not all their posts have it. When I've asked them if they knew anything about it, they didn't know it was happening.
It's an alien head inside a box.
I was wondering if my or their fb acct may have been hacked/has a virus?

[Zarn]

Does it look like the Reddit Snoo?

http://blog.reddit.com/2013/06/whats-snoo.html

If it is, then it is likely crossposted information.