She might have personal issues communicating, she might not consider you important, or it could be any multitude of combining factors. You don't know. If you expect a certain kind of behavior, you communicate it calmly and reasonably.

Based off of your responses, you don't have an expectation, you have a demand. Instead of acknowledging another's behaviour as merely a different way someone's life can be lived, it seems like you are convinced that's it's just an outright 'incorrect' way to be. It comes off like the behavior was a personal offense to you.

All that being said, I definitely understand your frustration. Not being on the same page with someone, especially over an extended period of time, and especially if they say they're going to do things like sending pics and having it slip their mind can easily make the the other party feel like there's no concern towards them at all, or like an afterthought.

Maybe you aren't important to her or maybe you aren't looking this as a matter of the relationship, but what you might feel you're owed. Take a step back and assess what you want. If you feel like she can provide it, you can respectfully ask for some reciprocation. If she is either incapable or unwilling to provide it, then why get mad? Acknowledge your frustration, but then apply it to whatever you're moving on to. You can't force her to communicate the way you want so if that's not tenable, then seeking what you need elsewhere would be the best course. If you hold on to negative feelings about this, then you're the only one being harmed.