If that data is encrypted (assuming no headers or footers or obvious block divisions), then it will appear to an attacker like random bytes. Whether or not that’s distinguishable from the original image depends on whether the low bits of the original image are observably nonrandom, and that’s not something I know offhand
It’s super-easy to spot in a histogram, so much so that there’s ongoing research into making it less detectable.
It’s super-easy to spot in a histogram, so much so that there’s ongoing research into making it less detectable.