How does Snapchat know you're sleeping?

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Tags

1. #actionmoji
2. #seemingly
3. #armchair
4. #snapchat
5. #sleeping
6. #state
7. #asleep
8. #snoozing
9. #while
10. #based
11. #appear
12. #people
13. #inactivity
14. #duration
15. #sleepy
16. #knows
17. #appearing