The staircase seen in the New York-based Greylight Auction Galleries showroom, with its distinctive balustrade, was previously used in the prior double-episode of the series - Nan's Ghost - where it was one of a pair in the grand hall of the ancient Irish castle.
When the 2 men confront Angus about his painting, Grey & Red, they show him the obituary of the man who died at beginning of episode. They pronounce the deceased's name, Randall, when the obituary shows it clearly as Rundall.