Any info/insight about this?

Hello everyone. Something wierd happened me while i was playing and i couldn't find any info about it. I must confess that i am new to the game and i have much to learn. So please, excuse me if this is a noob thread.

But first, images speak better than words.



I was playing like i normally do, when suddenly, the loot window appeared like this... I don't know if this is a bug or what... The numers started to change after every action i made. I'm posting some screenshots in succession for you to see.

Now some questions:
1) Is this a normal/known bug?
2) Did this happen to anyone before?
3) Any info, in general, about this phenomenon?
4) Does it have anything to do with loot calculation or it's just a visual bug?

Again, i remind you that i'm new, so if i did something wrong by posting here, i apologize in advance.

Thank you for your time.