Under British law, images can mean photos or videos.

Sounds like it would not cover drawn images. Which makes "making indecent images of children" sound quite bad.

“Making” indecent images covers a range of actions per its legal definition. It can, for example, include opening an email attachment with an image, downloading an image from a website to a screen; storing an image on a computer; accessing a pornographic website in which images appear in “pop-up” windows; or receiving an image via social media, even if unsolicited and if part of a group; as well as live-streaming images of children.

On the other hand, it seems that receiving an unsolicited image counts as "making," which throws actual severity of whatever he did up in the air again.