She has no reigns, she's not seen pulling on anything that indicates flight changes and only ever says one command; so how does she steer and aim? They could at least attempt to show some effort on this so the show will stand the test of the time instead of falling apart when watched again when the hype has warn off.
shareTargaryens have a mental connection with dragons. This is why drogon let jon pet him, and is also why drogon saved dany in season 5
shareOh. Is that in the books?
shareI can’t remember whether this has been mentioned in the books or not.
But in the show, there were various situations which can only be explained by a mental connection. The most notable one was when Dany attacked the slavers' fleet in Meereen (S06E09): She sits on Drogons back, passing the pyramid, looks down to the dungeon where she locked up Rhaegal and Viserion – and at that very moment, they break free.
There has to be a mental connection, because she has no other way to steer and certainly no way to tell her dragons what target she wants burned.
And that explanation does fit everything we've seen, and so does the idea that her mental connection with Drogon is much stronger than with the other two. The other two follow her and broke out of their basement when she wanted them to, but she only took Drogon into a battle that called for extremely precise flame-work. Too bad she didn't burn Euron's ships to the waterline when she had three dragons, that wouldn't call for any precision at all. Just set them all on fire and watch them burn.