You can call it whatever you want but people make inferences. Also there is no bright line between intentional and unintentional signaling. The brain is capable of hiding plenty of stuff from its own other parts. See the book "The elephant in the brain".
> You can call it whatever you want but people make inferences
This is an incorrect definition of a signal.
I agree that intention is irrelevant. But a powerful person blending in with their dress isn’t actually sending a signal. There is nothing to perceive because they look like everyone else.
The signal is only in if they’re recognized. Your definition of signal is congruous with any trait someone thinks a powerful person has whether it’s real or imagined.