The Room is an extension of the Hudson Bay Company's The Mirror Room, which was their high-end imported dresses, demi-couture etc. department. When Simpsons bought out the HBC in 1978 it was renamed 'The Room'. At some point it was closed, but I don't know when - I think it was in about 1992, and reinstated in 2009. This dress looks early 90s to me, so it was probably from the first incarnation of The Room c. 1978-1992.