Motion
Get Motion

ReferenceEffectsDistort

Mirror

One half reflected onto the other.

Kind
Effect · Distort
Script name
mirror

Settings

SettingKindStarts atRange and notes
ReflectsidechoiceLeft onto rightLeft onto right, Right onto left, Top onto bottom, Bottom onto top, Four ways
What every effect has

Every effect in a stack can be turned off, has an Amount and can be limited to part of the layer with a mask. They're listed on the effects page, and Effects and masks shows how to use them.