Henry's having a grand time teasing her, and she is so gullible and easy to tease! I don't know if it even mattered which room she'd be in; I think she's in a frame of mind that, no matter what Henry had described, she would have found things in the room & house that fit his tale closely enough to let her imagination outrun her reason. Catherine noticed the room's warmth, appropriate size, neatness, light, etc etc but all that was outweighed by the presence of a particular piece of furniture.