Here in Australia (Wollongong, Windows 7 x64) I get the turtle in chrome, and the snake in ie32, ie64 and firefox, private and regular. Mobile or no.
The turtle strip didn't seem to change any once you could see the turtle on his back.
Though the snake panels vary a little. Some panels disappear and reappear or only appear at certain widths. I started cataloguing them all but got a bit bored, it gets quite repetitive incrementing your browser window pixel by pixel. I got about 30 snaps and still had a lot to go.
Fully zoomed out I believe you should see all the major middle panels: guy standing in the middle of snake coil with swollowed thing and squirrel in one panel, guy and girl and ring in one panel, and the guy riding the snake and portal in the 3rd panel. The ends are almost mirror images. The little panels are just bits of the above big ones, plus a small coil. I think. There could be some easter eggs in there somewhere. You seem to be able to get every combination of the above, except for the big coil with the guy in the middle of it I can only see at full width (may need to open separately to see the full thing):
I certainly got the joke after an hour of searching for new bits of snake: "I found a snake, but then I forgot to stop".