What is hidden in 3D image?

A young boy, about eight years old, was at the corner grocery picking out a large size box of laundry detergent. The grocer walked over and trying to be friendly, asked the boy if he had a lot of laundry to do.

"Nope, no laundry," the boy said, "I'm going to wash my dog." "But, you shouldn't use this to wash your dog. It's very powerful and if you wash your dog in this, he'll get sick. In fact, it might even kill him."

But, the boy was not to be stopped and carried the detergent to the counter and paid for it, even as the grocer still tried to talk him out of washing his dog.

About a week later, the boy was back in the store to buy some candy. The grocer asked the boy how his dog was doing.

"Oh, he died," the boy said.

The grocer, trying not to be an "I-told-you-so" said he was sorry the dog died, but added, "I tried to tell you not to use that detergent on your dog."

"Well, the boy replied, "I don't think it was the detergent that killed him."

"Oh? What was it then?"

"I think it was the spin cycle!"