The glyph is not a composition. It has no designated width in East Asian texts. In bidirectional text it is written from left to right. When changing direction it is not mirrored. The word that U+0253 forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with one other glyph.
The Wikipedia has the following information about this codepoint:
Ɓ (minuscule: ɓ), called "B-hook" or "B with a hook", is a letter of the Latin alphabet and the International African Alphabet. Its lower-case form, ɓ, represents a voiced bilabial implosive in the International Phonetic Alphabet. It is used to spell that sound in various languages, notably Fula, Hausa and Giziga. It was also formerly used in or at least proposed for Xhosa and Zulu.
In Unicode, the upper case Ɓ is in the Latin Extended B range (U+0181), and the lower case ɓ is in the IPA range (U+0253). In Shona the upper case form is a just a larger form of the lower case letter.