I've never understood why some folk feel the need to jump up and down yelling 'finger off the trigger!' when they see a shot like this. She's supposed to look like she's intending to fire, that's the whole point.
I'm a shooter, safety's very important to me - I'm also used to being around guns on film sets and model shoots like this...and I've never had any problem with this kind of image, because it's fantasy, not reality. Done for dramatic or artistic effect.
Do you yell at the screen for the actors to "get their fingers off the trigger!" in war movies or cop shows? No, didn't think so. It's the same thing. Get over it.

Finger off the trigger!