Does the follower have feedback without signal input?

Discuss the matter and talk about the picture. Feedback refers to a "reverse transmission" of information from out to in - the main path is from in to out of course. If you have no idea, how can you talk about feedback? ! Of course, without emphasizing, what I said here refers to the "application of the concept of negative feedback in amplifiers." Others will not be discussed.

If it is said to be an "emitter follower", it is naturally "the emitter output follows the active input". How can one say "no input"?

When we say "feedback is a concept", we must understand it well ("define" when I hate it at all times).

The two virtual devices cannot be used in transistor amplifier circuits, but in most cases they are not virtual enough.