When you add an emoji over a face or similar moving object in a video clip, tracking is turned on by default. Tracking matches the movement in the clip to make an object appear to be part of the scene. If you want an emoji to stay in a fixed position in your video instead of following movement, you can turn off tracking.
With a video open in the Clips app
, tap the clip with the emoji whose tracking you want to turn off.
Tap the emoji, tap Disable Tracking, then tap Done.