A cartoon is a medium of:

A cartoon is a medium of low definition, offering little detail so that the viewer must fill in and participate heavily to complete the picture.

High definition names media rich in detail that leave little for the audience to supply, which is the reverse of a sketchy cartoon.

Neutral definition is not an established category in this scheme and names no recognised type of medium.

Negative definition likewise is not a term used to classify media by the amount of information they carry.

In McLuhan's terms low definition media are cool and demand high participation.

The bare lines of a cartoon invite the viewer's imagination to fill the gaps.