[dspillett]

They would probably come under some commonly accepted exception such as homage, humour, demonstration, reporting, and so on. The examples currently on this page the images in question are part of the page design so are functioning as part of a derived work.

Distinctions like this are rather fuzzy, but I think this sits the other side of the line most people would draw then the pages you mention.

(For reference, dear reader, in case the pages changes between me writing this and you reading it, the linked page contains stills from Back To The Future used as background images.)