Almost everything! 
Not a straight line out of the blocks. Very high heel recovery (you want it to stay low) etc… Having said that I watched her train a few days ago and if she sorts out the acceleration she will run 6.90/10.4x. At 40m her upright running technique is almost perfect in terms of achieving all the positions you need to maintain max velocity. I haven’t seen technique like this in a female before. Does anyone have any good slow motion footage of her when she was running slower from a few seasons back. I would like to see what has changed.