Run Nayuki, run like you never runned before!

This is as cruel as it is clever.

I hate to be the noob here, but I am totally lost. Are they radioactive? Or is that the chemical makeup of cat dander?

http://en.wikipedia.org/wiki/Iodine-131

http://en.wikipedia.org/wiki/Cesium-137

They're two radioactive isotopes released from nuclear reactions.

...ohhhhhh, I get it now.

...*nervous laughter*...well, that's disturbingly relevant...

Still, how can she see the elements? Is this a parody of another picture?

I'd suppose it's a play on a scene of her looking up into the falling snow (i.e. nuclear winter).

OhCrap said:
Is this a parody of another picture?

This image is a parody of the game cover.