The mega had the raw cannon images as well as standard jpg. They were huge files compared the the jpgs but a few had the extra data needed to make this shirt quite transparent.
For the photoshop nerds, this is the red channel, minimum filter, and histogram adjustments. that's all.
not sure if the bunkr included the raw cannon images, but looks like you get some high quality x-rays going with photoshop (these arent fake, just filtered images)