Feedback topology of a common emitter circuit
I think, the shown block diagram can answer your question. The resistor RE provides current-controlled voltage feedback. The well-known formula for the resulting gain can, of course, be derived from the block diagram.

Please not, that I have assumed IC=IE and I have forgottem a "minus sign" in the last block (-RC). This inverting property for the emitter stage comes from the fact that Vout is referenced not to the positive power rail but to ground. More than that, the series resitsor RS (in your drawing) is not relevant for answering your question - therefore, the input voltage Vin is identical to the signal at the base node.