The big 'inside' joke
It's based on a line of dialogue said by Marisa Paredes' character.
Anyone catch it?
Well, apparently not with no reply in a couple of weeks....
Regardless, after dinner, her future in-law (the gardener) asks permission to smoke something that resembles hashish. Paredes' character, an actress, indicates her approval in a "nothing phases me anymore" kinda way by stating that she used to work with Almodovar.
Thing is, anyone who's seen films directed by Pedro Almodovar will recognize Marisa Paredes as one of the actresses he's worked with.