Knowing it's the UK, it might even be a picture of a drawing depicting a childlike character engaged in a sexual act; it doesn't even have to be of a real child

Knowing it's the UK, it might even be a picture of a drawing depicting a childlike character engaged in a sexual act; it doesn't even have to be of a real child - it could even be something plucked from the artist's imagination (lolicon, shotacon, toddlercon etc.) Creating or possessing such a picture is a separate offence, but (stupidly if I may say so) still an offence.