Yes, you can just put the Buddy Cam on the frame as it is, but then you won't see the whole bed. This mount gives the camera a better angle, plus it makes is attached more securely with magnets.
The magnets are supposed to be the same as Prusa uses for the i3-series heatbed: 20x6x2 mm.
The author remixed this model.
I have combined the Ball Joint with the Buddy3D Camera holder, added sockets for magnets and optimized for 3D printing by cutting the ball in half.