How does the mirror in Las Meninas create mystery about the scene?

In Diego Velázquez’s masterpiece Las Meninas, the mirror on the back wall serves as a pivotal element that creates mystery by blurring the boundaries between reality and representation.12

The mirror reflects King Philip IV and Queen Maria Anna, implying that they are standing in the space occupied by the viewer, outside the physical frame of the canvas. This creates a complex narrative ambiguity: while Velázquez appears to be painting the royal couple, the Infanta Margarita Teresa is depicted in the foreground, seemingly surprised by her parents' arrival.12

By placing the reflection where it is, Velázquez forces the spectator to become an integral part of the scene. This technique transforms the work from a standard group portrait into a profound meditation on the act of seeing and being seen, leaving the true subject of the painting—whether it is the royal couple, the Infanta, or the act of painting itself—open to interpretation.12