This thread is primarily for photographers to get advice from other photographers on how to do photography stuff. I mean, you're photographer should be the one in here asking questions on how to make the shoot work because you're not going to be the one in control of the camera. That being said, if you were the photographer, I'd tell you to shoot low angles and have you in a crouched action type pose low to the ground, and have her stand straight up directly behind you. It would be best to use a wide angle lens for this low angle because it will exaggerate her height, making her look taller.
Another type of shooting would be to use different objects for here to stand on. Steps are a good example of this because it doesn't look like you're intentionally making her stand on something to increase her height. Don't use like a chair or a box. The photographer should also aim to do some shots where you're seated, like an a ledge, with her positioned behind you. You should also do a shot where she has you in a headlock giving you a noogy(sp). This doesn't fit her character, but it's a fun picture that emphasizes that fact that your character is a bit of a shrimp, at least in terms of size, not heart.
All of these examples will take care of the height difference and should make it a non issue. As long as you don't pose in your pictures like you're about to fall asleep, then you shouldn't have any problems with your own personality. Most of the time blackstar is rambunctious and generally aggressive when it comes to battle, so your action/fighting based poses should show you yelling, like an angry roar. Use this picture
as an example. Blackstar is also a bit full of himself, so you can do a thumbs up with a wink and a slanted grin for a more fun type of picture.
Again, everything I said here should be researched and known by whatever photographer you decide to go with, but having some information yourself never hurts.