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+01DD forms with similar adjacent characters prevents a line break inside it. The glyph can be confused with 6 other glyphs.
The Wikipedia has the following information about this codepoint:
Ǝ ǝ (turned E or reversed E) is an additional letter of the Latin alphabet used in African languages using the Pan-Nigerian alphabet. The minuscule is based on a rotated e and the capital form majuscule Ǝ, based on a reversed (mirrored) majuscule E.
It is not to be confused with U+2203∃THERE EXISTS, the existential quantifier used in logic, or with U+0259əLATIN SMALL LETTER SCHWA (uppercase Ə), which is used as a phonetic symbol and as a letter in Latin-based orthographies, such as Azerbaijani and the General Alphabet of Cameroon Languages.
In MacOS with the U.S. Extended keyboard, the letters Ǝ ǝ are made with ⌥ Opt+⇧ Shift+: followed by E e respectively.
The letter has been used by American rapper Eminem in order to stylize his stage name.