These next tests require cooperation. Consequently, they have never been solved by a human. That's where you come in. You don't know pride; you don't know fear. You don't know anything. You'll be perfect. — GLaDOS
Tony Stark isn't one to give out last calls and final warnings when he issues the Repulsor treatment. This time it's different, especially when he's using the Hulkbuster armor and he's dealing with the Hulk. But don't get him wrong, he has every intention to shoot... just with permission.
For the past 80 years, Marvel comics has told a lot of stories involving Tony Stark and multiple versions of the Iron Man suit. But regardless of the stories and accompanying changes, it always goes back full circle to the iconic red and gold armor design.
The EXA Phase is considered as the complete and final configuration of the Extreme Gundam Type-Leos utilizing the close combat capabilities of the Xenon Phase, the long ranged capabilities of the Eclipse Phase and the assault capabilities of the Agios Phase.
When Tony Stark saw Pepper Ports elegantly arrive at the battlefield using the Rescue armor, he thought to himself -- "Why the heck did it take me this long to give her a suit of armor!?"