A king bed is a wide, low object, and left on its own against a large wall it can look as though it has slid down the room. What fixes it is height at the sides - something vertical flanking the horizontal. That is the whole job the tall mirrors are doing here, and it is why they are shaped narrow and waisted rather than made as broad rectangles.
The proportion is worth getting right. A mirror that stops too low leaves a band of bare wall above it and the eye reads the gap; one that runs too close to the ceiling makes the room feel compressed. The comfortable place is usually somewhere in the upper third of the wall, and it depends entirely on ceiling height - which is why these are built to measurement rather than bought to a size.
Our master Indian artisans draw the whole wall at scale before cutting anything: bed, chests and mirrors together, against your actual dimensions. It is the only way three separate objects end up looking like one intentional arrangement.