To be fair I think that tweet was trying to make an argument based on proportions not height (which is still dubious since that's more an indicator of when you've finished puberty, which has a wide range of ages all of which are underage and there are disorders that can affect it) but had their head so far up their own ass they used their 250 characters to preemptively "own the lolicons" rather than have a structured argument, as Twitter users typically do.