If you look at the actual size (via Vizworld), you can see the full beauty of her mix of design, science & cartography. There's a nice touch with Sam giving the copyright to Transport for Body.
As Gizmodo said "And no matter what the locals tell you, don't take the pink line to the yellow line. That's nowhere you want to go."
Thanks to MichalD for letting me know about this. It's a lovely find and just when you think you've seen almost everything visualised as a Tube map, something else like this pops up. Harry Beck would be proud!