There is a support arm near jacking point, that transmits the weight to the crossrail, and further on to the body and chassis of the car. So you do not really make car hang on its engine.
You can also put jack under the support arm if you want.
Why not use 2 Jack's or ramps?
Perhaps, to avoid seeing what I saw in my first car, where raising at jack points only raised jack arms, but not the body of the car