The ejected brass seems strange. A P90 has the ejection port on the bottom and brass simply falls out around your feet. Good when you need take off after dumping a clip. Even if she was jumping down as it appears the brass should still go in a downward direction, not upward.

Tenshikuro said:
clip

That aside, you can see there are casings below the P90 implicating she's just sliding by that fast. At least it's more possible than the old version which didn't even have the casings below the gun.

she's not even looking at the direction the gun shooting. but nvr mind that