Although stated to be the seat of J. Black, Esq., this should actually be Alexander Black (d. 1835), who bought the estate in 1802.1

Note the couple in the middle distance, walking along a footpath towards the house. Perhaps they are returning from a stroll around the grounds, including a visit to the stretch of water that became known as Black's Canal - and is now the lake in Raphael Park.

On the grass to the left of the house you might be able to make out what appears to be washing hanging out on a line!

¹ Victoria History of the County of Essex, volume vii, page 68.