Mobile placement

Lynzi • 1 baby boy IVF miracle 🌈 1 preemie live birth, 1 ectopic, 1 miscarriage 💕 👶🏻👼🏻👼🏻 hysterectomy at 30
Okay so my husband and I keep having this debate on which end the mobile goes on in the crib. I say it's to go at the baby's feet so he doesn't really have to bend his neck to look at it and my hubby says to put it over his head so it's right above him. We're both first time parents so we're going in this blindly together. 
Which did/ do you do with your babies? I know neither one is absolutely correct, just trying to get some input from other mommies.