In the second board of Donkey Kong Jr. you come across some handholds that look different than the rest of the vines you've seen thus far.

They move left and right

and you have to make your monkey grab the left one and then gracefully transfer to the stationary vines on the far left.

So you reach out...

But, if you try to press 'Up' to start climbing instead of 'Left' to transfer over...

Junior's graphics kind of freak out. He's still playable and everything, and if you move him back into position, he goes back to normal.

I just think it's pretty interesting to see.

Oh, and it does not work on the arcade version of this game, so don't bother.