What does this even mean? And shouldn't it be a herb? (Not trying to correct you on it, I know you're just quoting, but I can't figure out how or why you would say an herb.)
Ahh, that would do it! I don't know if I've ever actually heard an American person say "herb" so I just assumed the "h" was pronounced like it is everywhere else! Thanks!
A/an before a word is dependant on how the subsequent word is pronounced, not spelled. So for that sentence, the implication is that it's pronounced closer to "erb", thus "an" to precede instead of "a". Another example that's a bit counterintuitive is "one" being pronounced like "won", so you'd get "a one time thing" rather than "an one time thing".
I wonder whether it doesn't have any inherent meaning. I mean, we all get the sense that it's an insult.
I say this because one of my favourite insult formats is "you [multisyllabic adjective] [random noun]. Stuff like "You incorrigible spade" or "You abominable turnip". They're next to meaningless, but my intention is clear
Well I think others have already sufficiently explained the grammar rule that applies to "an herb," so I won't mention it further.
As far as what it means, who even knows? However, it is clear from the context that it is meant to be a negative remark. This person made this tweet while upset after just resigning because the Kotaku CEO wants the authors to focus on video game guides rather than news, which the EIC says is in direct conflict "with her vision for the company." Saying anything unclear about the CEO with that context is obvious that it would be meant in a negative or disparaging way.