What is hidden in 3D image?

A farmer walked into a bar and saw the local tractor salesman sitting there, head hung low, obviously upset, drowning his sorrows in his beer.
"What's up, John?" asked the farmer.
"Gosh Bob, I'll tell you what ... if I don't sell a tractor soon, I'm gonna have to close my shop."
"Now John, things could be worse," said Bob.
"How do you figure?" asked John.
"Well, John - you know my ornery cow, Bessie? I went to milk her this morning and she just kept flicking her tail in my face. So I grabbed a piece of rope and tied it up to the rafter. Then, the nasty thing went and kicked the bucket away! So I tied her leg to the wall. Then she kicked my stool right out from underneath me! But I was out of rope. So I took my belt off and used it to tie her other leg to the other side of the stall. Well wouldn't you just know it...my damn pants fell down.
And John, if you can convince my wife that I was in there to MILK that cow, I'll buy a tractor from you TODAY!"