Follow these steps if you want to see who viewed your Instagram highlights on a mobile app:-
1. Open your Instagram and make sure you have the latest version installed in your device.
2. Then move to the bottom right corner of the screen and tap on your profile.
3. Then just below the edit option you can
view Instagram highlights.
4. Then tap on any of the highlights to see the viewers.
5. Then go to the bottom left corner once the highlight opens and then tap on the eye icon to see the viewers of that highlight.