I think there were/are questions about the age of the first alleged victim as to how old they were when the interactions first started and the nature of photographs exchanged, and they've been variously reported as being a young person/a 20-year-old/a teenager/a 17-year-old - I suppose this depends on when things happened and how old they were at the time. (Obviously hard to clarify given the alleged victim's right to anonymity.)
Some people have pointed out that * if * the initial contact was via a dating site rather than just social media more broadly, then such sites usually have a minimum age of 18, so it would have been fair for another user of such a site/app to assume the young person was 18 or older.
Others have pointed out that * if * an older person met with a younger person and * if * anything happened between them, there's not necessarily any crime involved, if both are over the age of consent, which is 16-years-old in the UK.
However, in relation to that last point, even though two people with a large age gap might be able to legally meet and engage in consensual activities, providing they're both over 16, a weird legal anomaly means that while in-person stuff might not be illegal, the issue of sharing/receiving/viewing photographs of a minor might be something that an older person could get into trouble for.
So people have been raising those kinds of issues, generally speaking, of course, because it's not known for a fact what happened, when, and how old the parties were were in this particular case when certain things are alleged to have been said/messaged and photos shared.