Why is there a black screen when remote accessing some android applications?

Question

Android

Hello. I have already used 3 tools to remotely control the android screen, but it turns out that applications like paxful, coinbase only show a black screen when they are opened.
Either this is such protection, or something else that
Android 5, Samsung S4 GT-I9500 phone

Answer 1

Most likely, it is: most likely, this is protection against remote reading of confidential information.
It is much more interesting to understand: how to do the same and with what?