The point of the Penguinbait Linux message is to let you know that you've booted from the flash drive, and if you have installed the Penguinbait stuff you presumably wanted to boot from an sdhc card.

And the point of the "pedophile" message is that the reaching hands pic is devoid of content and so can be interpreted different ways. Presumably they are intended to be a reference to the Michaelangelo paining, but that's not the only way they can be interpreted.

Advertising uses slogans and symbols in a deliberately vague way that is irritating, so it pleases some people to strike back against it by filling in blanks with unintended messages; I thought the van/candy message was very funny!