Although I do love the tease of sexual organs simply rubbing, I also love to see when they go in :)  This shows my fondness for this position as well, as it shows off all the active bits and penetration in such a great way.  I like how the dragon has an almost preditorial expression on her face as she takes pleasure in her conquest, and the gryphon's contrasts so much with the happy delight of having her sit on him :)