Mirror puzzle in HTBM (spoilers)

[ericthecleric]

We started TINH last week, and in Monday's session, the players solved a vault puzzle, although they found it very frustrating. For those who've DM'd HTBM, did your players find the "mirror puzzle" equally frustrating, or did they find it OK?

[Vigil]

I didn't get how the trap worked, and since I'm the DM, that's a problem. So I modified it to conform to the whole left/right motif. Sit in the left chair or light the left candle: trap goes off as described and the party is stil stuck in the room. Light the right candle and sit in the right throne and the portal opens.