This indicates that the bulb holder is designed to be mounted on a wall at an angle. It could have features that allow easy installation on vertical surfaces.
The B22 refers to the type of bulb base. B22 is a common bayonet cap used for various types of bulbs, including LED bulbs.
The mention of "B22 Bulb Holder for LED" suggests that the holder is specifically designed to accommodate LED bulbs. LED bulbs are known for their energy efficiency and long lifespan.