Problem with all these pictures is that they are from different camera angles and not say taken from the basket or at least the basket stanchion. Until I see pictures taken from dead straight on and preferably not from below it is impossible to judge the exact alignment or to compare the different players.
What I do know is that Stewart has an incredibly heigh release point, probably higher than either Maya or Kaleena though I am not exactly sure of that. And that she has a very repeatable motion that has led to her shooting a high percentage throughout her career. While everything may not be perfectly aligned on all her shots, that is true for every player as well, and if her 'prefect form' shot is not exactly aligned I don't think there is any analytical data that suggests say a 5 degree change in angle on an elbow results in a change in accuracy for a specific player. Human bodies are infinitely variable and while you can say statistics prove that for the 'average body' this is the best possible, most repeatable, and simplest form - finding that 'average body' will take you the rest of your lifetime and your heirs lifetimes.
And she has had some bad shooting nights as have every other great shooter I have watched regardless of their form.
I will also admit that as a whole this year while Stewart has been playing at a very high level, she has not been shooting quite as well on the year as I expected, but that is as much a factor of her having missed a number of layups hooks and scoops around the basket that I don't remember her missing last year as her distance shooting, and those shots are completely different from her jump shot so have no bearing on this discussion.