I've been to serveral petstores, in MA, MI, and FL, that have done this.
If I had a petstore I would be tempted to do something similar, but only if I had the space necessary to set up the animals exactly the way they should be, not a typical petstore display setup. It would give customers a better understanding of what they would need in order to properly house their pets for life. It would also advertise the type of animals that I'd be able to order in for sale, and hopefully boost supply sales if it was advertised that replicas of those custom enclosures were also available for sale.
Sadly, most stores with in-store pets that I have seen don't do it this way.