Ask, Then Go Quiet

When you finish a mirror statement, stop talking. Add one open question — "What do you notice?" or "Does that match your experience?" — and then be quiet.

Silence is the mechanism. Most feedback fails because the giver keeps explaining and re-stating until the other person disengages. The mirror plus silence does the opposite: it hands the floor to the receiver. Three seconds of silence feels eternal to you and perfectly normal to the person thinking. Train yourself to tolerate it.