LEAVING BABY IN HIGH CHAIR - ALL MOM'S

Quick question for all moms! Have you ever left baby in the high chair and left unattended? If so how long and what were the circumstances? Asking cause the person I know will leave her baby in the highchair and lock her self in her room and talk on the phone with her girlfriends.....I don't have a baby, but it makes me feel uncomfortable and like I have to sit there until she comes back because he could get hurt or choke on something. Another thing.....she will sometimes leave him in his play pen and go take a nap........while he is awake. Am I wrong to think something is not right with that? I just feel like that is not something I would be doing if I was trying to raise a baby.