Much of the humour involves the interaction of the play-within-the-play with the play-not-within-the -play. The play-not-within-the-play doesn't really satirise the farce of the play-within-the-play, but adds an extra dimension to it, remaining true to the spirit of farce while producing a particularly clever and hence particularly funny one. Convolution, thus, produces refreshingly simple but winning humour. Everyone laughed a lot, and there were wild cheers at the end...