The painting depicts Van Gogh's bedroom at 2 pm, Place Lamartine in Arles, Bouches-du-Rh么ne, France, known as his Yellow House. The door to the right was opening to the upper floor and the staircase; the door to the left served the guest room he held prepared for Gauguin.
The window in the front wall was facing to Place Lamartine and its public gardens. This room was not rectangular but trapezoid with an obtuse angle in the left hand corner of the front wall and an acute angle at the right.
Van Gogh evidently did not spend much time on this problem. Somehow he simply indicated that there was a corner.