This character is a Other Symbol and is commonly used, that is, in no specific script.
The glyph is not a composition. Its East Asian Width is wide. In bidirectional text it acts as Other Neutral. When changing direction it is not mirrored. U+1F9CE prohibits a line break after it, if it’s followed by an emoji modifier.
The CLDR project calls this character “person kneeling” for use in screen reading software. It assigns these additional labels, e.g. for search in emoji pickers: kneel, kneeling, knees, person.
This character is designated as an emoji. It will be rendered as colorful emoji on conforming platforms. To reduce it to a monochrome character, you can combine it with Variation Selector-15: 🧎︎ The character can be changed in appearance, if it is followed by an emoji modifier. See the Emojipedia for more details on this character’s emoji properties.
The Wikipedia has the following information about this codepoint:
Kneeling is a basic human position where one or both knees touch the ground. According to Merriam-Webster, kneeling is defined as "to position the body so that one or both knees rest on the floor". Kneeling with only one knee, and not both, is called genuflection.
Kneeling is a primate behavior used to convey deference by making the figure that is kneeling appear smaller than the other. Primates themselves establish a dominance hierarchy (or "pecking order") which is important to the survival and behavior of the group. Chimpanzees, for example, have a complex social group that involves a dominant male and a corresponding female, to whom the other males and the juvenile chimps are submissive. Males who threaten the hierarchy are often severely injured or killed; in some instances, the use of submissive behavior is necessary to ensure survival.