The feature is called emergency egress, the higher grade Schlage you can find in Home Depot have them, otherwise it’s not typical of crappy locks. The idea is that if you’re escaping a fire, burglar, or uncle joe, you’re able to leave without having to think about unlocking the door in a panic. Trust me, If you see uncle joe in your house, you will be panicking. Lock hardware in Home Depot is typically trash.
As for how it actually works, the inside knob is not directly attracted to the lock actuator like the outside knob is until it’s turned to a certain degree. Turning the inside knob to that degree makes contact with the actuator and unlocks the door for the outside. The lock actuator is a long rod (ha) which the back end you turn to lock or unlock it.