I could definitely see the hulk buster scene being a sparring/test with Banner. But more than likely Ultron has hijacked it.
Look at it this way: Hulk is definitely attacking the Hulkbuster suit in that scene. The Hulkbuster is grabbing Hulk's fists, meaning he's *blocking* an attack.
So yeah, it could go either way: out of control Hulk with Tony coming in to try to stop him, *or* out of control (i.e., Ultron-controlled) Hulk
buster with Hulk trying to stop him/it.
I'm betting on the latter.
That's gorgeous. I wonder what Tony & Bruce are working on there? Hopefully something that can take on Ultron.
I don't think that the image of Tony is exactly copied from IM3 art. But then again, I don't give a **** if it is. It. Does. Not. Matter.
Hard to tell since the figure is in the background, but in general, he seems to have darker hair than Steve Rogers, Clint Barton or Pietro Maximoff. Bruce is a safe guess....
....His pose is kind of telling, there. He's standing with his hands behind his back, like he's waiting for something to happen. If he was there to help Tony, or just curious about what Tony was working on, he'd be standing right beside Tony and his work. Instead, it looks like he's at the end of a beam weapon, getting ready to (willingly) get blasted by it...
....in sum: I think Tony is trying to use reversed arc reactor technology to "cure" Bruce Banner, and literally blast the beast out of him.