To answer that question accurately, we need a few things.
1.) Conformation pictures. One picture taken from the side of her standing square on flat ground, top of the head level with the withers. One picture of her from the front, showing her legs, and one from the back, also showing her legs, and with the tail pulled out of the way.
2.) Pictures of her under saddle. Does she frame up? Does she lack thrust from behind? If you're advertising her as a trail horse, pictures of her on trail crossing water, riding with a group of people, riding solo, etc.
3.) Videos of her under saddle. We need to see the correctness of her gaits, how she carries herself, if she comes up to the bit or fights it, if she's go-ey or lazy, we need to see that she is a calm trail horse.
4.) Videos of her in hand. Buyers want to see what she can do. If you say she does shoulder-in, backs up, and sidepasses, they want their proof in a video. If you say she does auto lead changes, you better post a video showing her auto changes.