⟨ZWJ⟩
The invisible weld: three emoji and two ZWJs make one family.
The zero width joiner asks its neighbors to fuse into a single glyph. It is the alloy of emoji sequences: the family 👨👩👧 is literally 👨, 👩 and 👧 welded by two ZWJs.
In Indic scripts and Arabic, the ZWJ requests the joined form of a letter where it would not come on its own. The entity is ‍ — and deleting an emoji family exposes the weld: each Backspace removes one stone at a time.
Apart: 👨 👩 👧 (three people)
With ZWJ: 👨‍👩‍👧 (one family, one glyph)