Final answer:
The painting that features a mirror in the background that perfectly reflects the objects in the foreground is 'Las Meninas' by Velázquez.
Step-by-step explanation:
The painting that features a mirror in the background that perfectly reflects the objects in the foreground is Las Meninas by Velázquez. In this painting, Velázquez includes himself as one of the subjects, standing by a large canvas and not looking at the potential subjects in the room. The mirror in the painting reflects the figures of another man and woman.