LG 27BR550Y-C Owner's Manual page 6

Pivot Feature
The pivot feature allows the monitor to rotate 90° clockwise and -90° counter clockwise.
1
Raise the monitor to the maximum height.
2
Adjust the angle of the monitor in the direction of the arrow as shown in the figure.
6
3
Rotate the monitor 90° clockwise and -90° counter clockwise as shown in the figure.
4
Complete the installation by rotating the monitor 90° clockwise and -90° counter clockwise as shown
below.