Steady hands mean steady reins and especially in the canter they are going taught-loose-taught-loose. You can see the expression in the horse that he is not too impressed with being jerked in the mouth every stride. The hands are very rigid and fixed. Not steady.
Overall your aids are very passive and you are very posed. The first thing I would do were you my student is get your hands down to the withers so you can feel where the motion of the horse is going so that your arms are not so rigid and catching the horse in the mouth every stride. Then I would take away your stirrups to try to get some movement into your seat. Right now again, because you are so rigid and posed, you are stopping the horse with every stride and digging a hole in his back.
Once everything is not so blocked, then I would start with some leg yields and things, but right now I don't even really see a leg yield, because your other aids are all blocking the horse he can't actually do a leg yield.
Really think about flopping like a sack of potatoes into the tack and letting the horse move your body. Until you can move with the horse, you will not be able to put an aid on in the correct timing. Your posture is good. This is why I say correct equitation goes way further beyond thumbs up and heels down. Because by a book your equitation is good, but ask the horse or get into a real life riding situation and it falls short.
They say money doesn't buy happiness -- well happiness doesn't buy horses!