It's quite a bit different than Stingray City in Grand Cayman where there are tons of boats and the stingrays all come up and "bump" you for food. The Disney experience is very controlled with small group sizes and rays that are trained to swim up on a platform for the food. You can snorkel in the stingray area once you are done feeding them but most hide under the sand so you won't see a lot.
Interesting bit of trivia: back when there was a hurricane a few years ago, the netting blew down and the rays all escaped. However, almost all of them returned...they know where to get the free food!