Pretty much what the title says. X would be an acting category that the GM could enhance for the player and the the player could role play better in and of themselves. Anyway, one question with two slants or two very linked but differently focused questions?
Assuming X is a characteristic of a PC/NPC, it would depend on how much of a difference you guess that being a DM will make. Generally, this won't be much, but there are some instances where it's extreme enough to warrant splitting the question (prophets come to mind).
If the questions is about how a DM can help a PC expand on their role playing, I'd say that warrants an independent question and shouldn't be tacked on to a "how do I roleplay X" question.
Examples: "How do I roleplay as a snake?" will generally be a similar question, whether you are a GM or a player.
"One of my players is roleplaying as a snake, how can I help them?" is a distinct question from "how do I roleplay as a snake?"