The selfie is 1) of incredibly low quality and 2) depends on where the source got it from--did they get it from the court filing (in which cases they got it by doing a screenshot from the pdf of the court document), which is where most news articles got it from originally or did they do a screen grab from the Amazon special (which was also likely from a screenshot of the pdf of the court document--so that's a screen shot of a screen shot).
This is the court document that had the photo (scroll all the way to pg 17):
You'll notice a lot is off about the picture--the background has a weird pink tint to it as do the bathroom shower tiles and his white dress shirt. The original image would have had plenty looking "off" about it because it was taken in a bathroom under what was likely fluorescent lighting, messing up the colors. And from looking at previous BK selfies from years prior to this, the boy can't take a good selfie--always too dark or too washed out.
The official AP photos of the plea hearing have the issue of being taken with him in front of a semi transparent white window covering in the court room on a sunny afternoon. That light as well as the extreme shortness of his hair on the sides makes the hair look lighter. Even the top is shorter, so he's got less hair product in it, making the top look lighter than when his curls on top were longer and full of a lot of hair product to tame them the way he wants. I've only found one photo of him where he wasn't directly in front of that window, and even in that photo he's only just off to the side of it:
https://i.abcnewsfe.com/a/a545f592-...rger-03-ap-jt-250702_1751477525301_hpMain.jpg
(from this article:
Bryan Kohberger admits to Idaho college killings in plea hearing)