First off, holy shit where is this clip from?
Second - it took me a good 5 minutes to realize that the recoil's yanking her hands down - that's not how recoil works, is it?
The reason her arms are being pushed down is because her hands are too low and she locked her elbows. The force is pushing from the barrel backwards and using the point between her thumb and index finger as a fulcrum, rotating the gun barrel backwards and up. It should be rotating her hand in the same way, but since she's locked her wrist and her elbows, it's translating that force into downward force and pushing her arms down.
In some modern guns part of the exhaust is vented upward from the barrel itself, this sounds counterintuitive to preventing your arms moving downward, but again, if you understand the fulcrum, the gun barrel is being rotated upward which is causing the push on your arms downward, so countering that rotation prevents the arm being pushed down.
Did a lot of edits as I recalled the actual physics.