Thanks for that. I find myself increasingly bugged by this kind of argument by misleading analogy. "X is like Y. You agree with me about Y. Therefore you must agree with me about X." It basically frames the entire argument around the differences between X and Y, rather than taking X on its own terms.
It's kind of galling, since it basically assumes that I'll agree that X is identical to Y. Therefore, either I'm stupid for not realizing that X and Y are identical, or you're stupid for not recognizing that there are meaningful differences. I'm betting it's the latter, but even without that assumption, it's hard to see how we proceed from the demonstration that at least one of the parties to the conversation is stupid.