If you look carefully they are not floating. There are holes on the side panels and obviously use shelf pins.

If you want floating shelves...lowes does sell the hardware and glass shelves. The shelf is only supported at the back wall, but would not be as deep as the shelves pictured here.

Hello, thanks for your question. Kivi is correct, we used pins to float the glass. it's a simple solution and not very expensive to do. Fully floating glass is more complex and takes more detailed design / coordination with the craftsmen