If you illuminate the rotors with very brief, very bright, flashes of light then you can use a camera with a much longer exposure suitably synchronised to the strobe flashes to take pictures of them, and they will appear stationary. This means you can get a good idea of what deformations the blades are undergoing. This is a common technique for looking at ...
Let's ask ourselves
How does Ingenuity start moving forward?
How does Ingenuity steer?
The same way a normal terrestrial helicopter does and not the same way a quadcopter does. From this (frighteningly thorough) answer to Why Ingenuity drone has 2 coaxial rotors, not quad-rotor:
The way a helicopter works (and the way ...