What does this picture demonstrate?

It demonstrates optimism.

That young giraffe is obviously try to climb onto duck's back to go for a flight but, like I told Orville, and I told Wilbur, it'll never get off the ground.

That giraffes  when running  always keep three feet on the ground at all times

I can't think of anything funnier than the 3 feet on the ground running answer.  I'm still laughing. 

That the giraffe can't be trusted with a secret.  He immediately turned the duck in for the murder of the tiger.

Coincidence.

If it looks like a duck and walks like a duck, it's a duck.
~

It teaches one  to not seek meaning where there is none. This post was edited by Benedict Arnold at March 20, 2017 10:22 PM MDT

Magic giraffe turns  'The' Donald into a duck. This post was edited by Kittigate at March 21, 2017 3:51 PM MDT

Human can impose a narrative onto a juxtaposition images.

1) The original photo (assuming it has not been manipulated) with anthropomorphization
2) The use of typography and text
3) A visual parody on a popular graphic poster series (shared cultural knowledge)
4) Play on words

Giraffes  can do the Dabke.

Giraffes can point.

Giraffes can point.