For this to make any sense, there has to be an accepted distinction between a "fan" and a "true fan", "real fan", etc. Otherwise, they've already acknowledged they don't know what a "fan" is.
My hope is that the last panel addresses that bit of nuance enough, but I'm the person writing this. I won't be entirely sure if I'm being clear enough until people see this.
Actually, let me take something back. There doesn't have to be an "accepted distinction". Part of what they're discussing is whether that distinction exists at all. What there has to be is the possibility of a distinction.