I believe today at his signing of tariffs.
Right after the 14 minute mark, and IIRC Cboldt posted a link to the video; check his comments and you may find the video. I watched the part right after 14 minutes and he does say “mirror” two or three times, in referring to some taxes, and says “set the stage” and makes an unusual gesture with his R hand in the air which is suspiciously Q looking.