Concealing their faces is fine.
Not showing them at all leads many people to believe that most look like the strapping 6 footer with the white scarf around his head and not the little kid on the purple pushbike.
If we've learned anything from the EU Referendum, it's that the British people have had enough of being lied to.
Would have thought if anything that proved we prefer lies

To be fair short of mugshotting each and every one of them some people are never going to be happy. Seems unfair to make such a spectacle out of them in the media since they're just kids(or at least the majority probably are).