Oh my mistake, it looks fine though to me, the first pic with the air makes it look like the left side is brighter than the right but I don't see it in the standalone picture of the phone so I guess it's your camera maybe, or the angle.
The picture with the iPad is definitely the camera angle as the left side is for surely darker. and FYI the left side of my iPad screen is slightly dimmer too so that's not because of the camera. Funny thing is i've had that iPad since December and I never noticed the unevenness until recently let alone have it ever bother me. Yet it's driving me bonkers on the iPhone