Why is my hair only curly at the very top?

I had my first curl cut recently. Only the top was curly, the rest straight. My hairdresser said the hairs at the side and back are too short to form curls, but some of the curls on top are the same length! Is it even possible to only have curls at the very top? I'm really worried the curls will never come out. I don't know what to do with my hair!!!!

Also, the last picture is what was taken the day I had my curl cut. I had gel put in and it was diffused (I don't have a diffuser myself yet so air dry). Also, my hair looks like crap in the pictures, so sorry. That was a bad hair day for me as I was experimenting with the denman brush (I usually just rake with gel).