As an experiment, I uploaded and had accepted four images of politicians which with isolation, simplification and several filters and tweaks are now cartoons.
As I was 'managing' them, I wasn't sure whether to classify them as 'illustrations' or photographs (digitally altered).
I have them currently as 'illustrations', on the spurious grounds that I have photographs (digitally altered) that maybe have a bit of litter or pavement chewing gum digitally removed but are essentially 'as was'.
Certainly, these are manipulated photos. Equally certainly, someone with more artistic ability than I could have come to the same result manually, either using the photos as references or from scratch.
Any definite requirement?