You make the rules on what counts for you. There is no rule other than no porn.

If you feel like you don't feel right masturbating to images of your girlfriend because of its pornographic nature, then don't do it.

Just remember that this isn't a no fap sub.

Your girlfriend WANTS you sexually, that's why she's sending you these images. In my own opinion, there is nothing wrong with viewing her in that way and seeking sexual gratification from that because you are both consenting adults who are sexually attracted to each other. That's your girlfriend. It's not like she's a stranger who is being sexually exploited for those images. You have a trusting relationship, and if she's sending those images to you, then I'm pretty sure she consents to you sexually objectifying her in that manner. It could even help consolidate your relationship with her if you agree to only use photos/videos of her.

If you say you don't want to fap to her and you're kong distance then you're essentially completely eliminating that sexual element of the relationship until you see her physically. Only you can decide if that's good for you and for her.

If you feel like those images/videos will send you down a rabbit hole of porn and you'll find it triggering to go back to porn, then don't do it. You need to decide the parameters of what is good for you. Nobody can decide for you whether you should fap to your girl or not. Only you decide that.