I think it’s from Turnabout Intruder, the last episode in the last, third, season. A crazy female wants Kirk’s job and decides the way to do it is change bodies with Kirk, so Shatner plays a man/woman trying to mimic Kirk’s mannerisms, but who is still uncontrolled crazy, and the guest plays a woman/man with Kirk’s instinctive mannerisms. It gets sorted out by Spock mindmelding the woman and recognizing his captain.
Turnabout Intruder...
Watched it last night.
It looked like an outtake perhaps.
But Not in that broadcast episode.
Very weird episode indeed.
Whom the God’s Destroy....
Tonight.