Analysis of a speech:
1) Aims of a speech (download)
2) Means and effects (download)
3) Elements of speech analysis (download)
4) What makes a speech effective? (download)
literary humour
verbal humour
(=something funny in the way of presenting/phrasing it).
It relies on the means by which the person, object or event is described, and is often dependent on the element of surprise.