Halliday & Matthiessen (1999: 584-5):
This 'world view' can be depicted using the conventions of comic strips: see Figure 14-7.
The conventions of comic strips clearly differentiate between figures of sensing and saying on the one hand and figures of being & having and doing & happening on the other: the latter are represented graphically, whereas the former are represented linguistically, in terms of their projected content Comic strips thus codify the higher-order nature of projections and their constitution in language.