Couple reasons why this 'Elvis film' works so well
1) It was well directed by George Sidney. He keeps the camera back and
doesn't push in for a lot of close ups. You get to see what's going on
in a scene. He's especially smart in doing this in the dance numbers;
when Elvis and Ann-Margret are really working it (and they both can
move) you get to see the whole thing. You'd be suprised how many directors
today would splice in some unnecessary head shots in the middle of a
dance number.
2) This film is a definitive example of "screen chemistry" between
the two leads. There is nothing a studio can do if it isn't there.
No rewrite or change of directors can manufacture it.
And we all know that chemistry spilled off screen, as well....