True, the motor does not know. The Pico Shutter does detect the end positions (presumably via its power measurement capability*), and remembers the total time between fully open and closed, and fully closed and open. (These are not the same because Up takes longer for heavy blinds.)
Unlike with traditional switches, the motor doesn’t sit in its end position fully powered if you leave the physical switch on. The Pico Shutter turns the relay off.
*The Pico Shutter shares the same hardware as the Switch and Switch Duo, and these expose power meters.