Is this watch a … manual winding or a self winding watch?

How to ditinguish -without using catalogs or the internet- among manual winding and self-winding watches?

In case of sapphire case back, the answer is easy: if you see the rotor moving, it is a self-winding watch!

But if the back is closed, you need to pay attention to weak signals…
For example, charging a manual watch generates a series of TicTac, one separate from the other, while a self-winding watch a sort of continuous swish.
Moreover, moving an automatic watch with wide movements makes the rotor swing, producing a sort of buzz, that obviousely may not be emitted by a manual watch.