My interpretation is that this conversation had many layers. One of such layers was that the Trump team claimed Zelenskyy campaigned for the opposition, Kamala

My interpretation is that this conversation had many layers. One of such layers was that the Trump team claimed Zelenskyy campaigned for the opposition, Kamala Harris. And one of the objectives of this whole situation was to frame the discussion as a humiliation ritual or character destruction to show what happens when you are not aligned to deter others from doing the same in the future. Shaming individuals who are not aligned is a recurring theme in rallies. e.g.: "Do you see this? Do you want to be seen treated like this? don't campaign for our opposition".