According to Fiorelli and Eschebach, originally this was a deep shop with stairs to upper floor and latrine underneath them.
See Pappalardo,
U., 2001. La Descrizione di Pompei per
Giuseppe Fiorelli (1875). Napoli: Massa Editore. (p.96)
See Eschebach, L., 1993. Gebäudeverzeichnis und Stadtplan der antiken Stadt Pompeji. Köln: Böhlau. (p. 288)