Yes, this 2nd ipad3 64/4g does have a little backlight bleed, about the same as yours I would say, but in normal use, and by that I mean normal lighting conditions and normal brightness levels it's not visible, and is definately not detectable in normal use, so I'm not going to change it unless something else prompts me to do so.
As you may have read, my 1st one was changed at our Apple store yesterday simply because on the 2nd day of use I started to notice a 1mm fine dust partical on the screen befind the glass. TBH it wasn't too bad as you had to know where to look to spot it, AIS I didn't notice it at first, but as it was there all the time and would be visible for ever more, and as I had reason to visit Birmingham, Apple Store in the UK, so was going withing yards of the place I figured I may as well change it.
BTW, my 1st Ipad3 had virtually no light bleed at all when viewed in the dark, so for me, though I resolved one issue, I came back with another, though in fairness I consider this light bleed to be less of a problem.. simply because it's not visible under normal conditions... IOW under normal viewing conditions the problem does not exist. Be honest with yourself.. watch a movie in normal conditions with your iPad set at a proper sensible brightness, and see if it's visible. If you can still see light bleed at the edges get it changed again.
It is very easy to become a little paranoid with these sort of things as we all want something to be 100% perfect, and in theory of course it should be. Only problem, some of us are more fussy than others, usually the likes of us who are sad enough to read and participate in these forums...lol In your mind your minor light bleed gets bigger everytime you look at it, and you likely cannot resist the temptation to check it over and over again.. in effect I am not just discribing you and me for that matter, but it's just human nature.. I would be discribed as being a very critical fussy person, so I can assure you, you are not alone...lol But only you can decide.
Me personally, I'm sticking with this one and not returning it again unless something else arrises, as mine is not noticable when viewing normally.
In fact, I have already decided in that event I will simply just go for a refund instead and stick with my iPad 1, which BTW also has some light bleed around 1 edge probably worse than this iPad3 but during the 18mths I've had it I've never noticed it...lol
BTW I noticed yesterday that Apples 2weeks grace period restarts from day of swap when they give you a new replacement, which is good.
But you still didn't answer my question.. Why are you photographing it in the dark? & of course we both know why, you would'nt be able to see it otherwise, read my reply above a second time.. and decide.. or on this occasion for you maybe a refund may be the better choice if that option is still open