It was the same reaction as a song getting stuck in my head where I keep singing it throughout the day. When I was a kid, I distinctly remember watching an episode of the aliens in Sesame Street like this one.
What made me remember it to this day, are those aliens repeatedly saying "Yep, Yep, Yep" ad nauseam. It stuck in my head, and I know I spent days walking around the house annoying my parents and brothers responding to everything they said with the same, distinctive response.
To this day, I still catch myself having the alien image and internal response when surrounded by others who always agree with the leader on everything. I can't stand it when I am encountered by mindless, agreeing aliens! No matter what is being said, followers line up responding with, "Yep, Yep Yep".
They agree with whatever the leader says...no matter what. All the time. But, at the same time, I am equally as frustrated when leaders intimidate or combat responses adversarially, only to coerce others to agree or else suffer the consequences. Even more frustrating than that, I hate it when I walk away from a meeting reflecting on my own alien response buckling under the pressure or pleasure of the leader, instead of focusing on the goal or issue by providing feedback or an idea I think may be better.
The problem is that the leader may not be aware they are surrounding themselves with aliens, but they need to expose them right away. A litmus test in determining whether you are surrounded by aliens is reflecting on whether you have been challenged or had push back on ideas recently. Being challenged, in a professional manner, is healthy.
Leaders should overtly develop and cultivate a healthy "Team Dissonance", in which members share their ideas without repercussions. Team Dissonance is a fundamental belief in productive teams which understand the collective genius of the room.