mooncow - Xanthippe used the quote found in the ODQ, it's the standard reference for quotes for crossword editors. Luckily there's another route for solvers who don't have a copy (a wiki page) and even here the quote is referenced and given precedence (the 'real' history is neither here nor there). By the way, the wiki page fails its own accuracy test by omitting the word 'is' from the quote, but at least it directs us to the facsimile, where we see it in full.
I think the illustration is simply generic and any resemblance to a film or advert - or anything else - is probably fortuitous. When I started on the endgame the first thing I looked for was a stick-man. I knew it would have to be something simple and symmetrical - and I'm sure it would have got me thinking about old TV episodes of 'The Saint' if I'd found it, but that's irrelevant (I think).
As I see it, Xanthippe has simply linked the two elements of the quote within a crossword puzzle. We get the one thing within the many things (although not that many) mentioned in the quote - for me, it's a neat end to a very novel grid-fill.