Speaking in a fake cockney slang. This is accomplished through speaking at a high rate of speed, saying a combination of things American tourists would take pictures of while on vacation in England, as well as places they might travel on a train, punctuated both by either starting or ending every phrase with a question.
Examples of Mockney:
Pip pip, cheerio! Me thinks Gillingham trolley-car newspaper phone booth! Jolly good mickey, ehar?
Westminster double-decker? Right old rain coat!