It might be temporary as they are getting only one Gravity. They'll want as many folks as possible to check it out, it is easier if it's stationery in the studio, than in between demo drives.
In WA state, demo drives are still unallowed for car companies not selling through dealerships (except Tesla who got an exception), and only earlier this year Rivian and Lucid found a loophole through "educational drives", so it can also make the managing of demo drives complex.
The Lucid studio in Seattle has 3 cars spots with AIR for educational drives, so I guess once they can, they'll add the Gravity to the roaster.