I think one of the things that inflate image counts like that is that if there is a video of child porn, each individual frame of the video is counted as a single image. If he downloaded a 40 second, 60 FPS video, that’s 2.4k images right there.

This is why it’s more interesting when they mention total size in gigabytes of whatever, because image data has a maximum compression size but “raw number of images” is completely made up and could be a single file even when in the tens ouf thousands (still bad of course but you get my point)