In the screenshots, you can see Nikola wearing his exosuit immediately before singing a lullaby to the egg in an incubator. As soon as the animation of him hugging the incubator begins, his exosuit helmet disappears. (And it returns when he leaves the incubator.)
Steps to Reproduce
Have an incubator in an area where a exosuit is required to enter. Put a critter egg in the incubator. Watch when a dupe goes to sing a lullaby.
This issue has not been confirmed by a developer yet.