It took me too long to figure this out.
At the moment I need to take the wheels off the chair when putting it in the car. This means a bit of juggling (standing with my weight mostly on one foot, of course) to take the wheels off. Once I made this discovery, though, it got a lot easier...
The chair will balance on the front footplate, not just with the wheels off, as shown, but with either or both wheels on.
Someone thought about that.