The artist Brocktorff is well known for his paintings of Malta. This image is a preliminary study - or unfinished sketch - in pencil and is likely the starting point for another watercolour in the collection. The room is the northwest corner of the antechamber in the Grandmaster's Palace, Valetta, and for a rough sketch, this piece is very detailed.
Vella, Theresa. Charles Frederick de Brocktorff: Watercolours of Malta at the National Library, Valletta – Volume II. National Library of Malta, 2008. 149-151