The magician "hypnotizes" an assistant and commands them to recline on a table or couch.
As the magician pulls off the cloth, the assistant vanishes instantly.
This illusion is credited to Servais Le Roy and was first performed with his wife as assistant in 1902.
When the assistant lies down on the couch the form is quickly moved on top of her while the cloth cover is being deployed with a flourish.
The wires making up the form are thin enough that when the cloth is removed, they cannot easily be seen against a complex backdrop.