What’s it for / do?
Robotic invasion on load screen, I think.
All I recall seeing was a 50% loading screen, complete to 100%, and then a big nothing. I checked the settings and it still said R73 version. I did see someone post an Ultron loading screen with updated Daken covers in a post earlier but they did mention that they play on steam. Not too sure how true that was.
New cover art for Ares, Daken, and Quicksilver too. I actually kind of liked Quicksilver’s cover though
Just updated to R74 and all listed changes are in.
And now I have ANOTHER update that won’t even let me access the game, til it’s downloaded…
I updated on mobile, and now I can’t get past the loading screen. The one where the icons rotate…
Daken art is a bit confusing as a thumbnail but it’s pretty cool when full size.
I got the Ares in my first fight and thought they had secretly added a brand new 2* named Seige. 
I unfortunately have this issue to. and it seems like many others do as well. Hope D3 fixes it quickly
This is just my speculation, but I believe they replaced the previous Daken covers, which were pretty bloody, to make it more family-friendly. We’re all anticipating a user bump as the Avengers movie hit the theaters, right?
No blood on Quicksilver, though. I definitely prefer the new “old-school” QS cover. 
What was annoying about this update was the game wouldn’t let me play until I updated. I’m on a tablet without a cellular internet connection, so I didn’t need to wait for a wi-fi connection (I can’t play if I don’t,) but it was still annoying to have to update on their schedule rather than my own.
I could definitely see this being disasterous for someone on a cell phone.