How come I sometimes have options after hacking an enemy?

Sometimes, while hacking an enemy as 9S, a prompt comes up that allows me to choose what to do with the machine lifeform I've just hacked. Instead of simply detonating the enemy, I can choose to turn the enemy hostile to other machine lifeforms or I can control the enemy remotely.

Is it just chance that allows me to do this or am I doing something I'm not aware of?

Solution 1:

While not explicitly mentioned, you will have more options available to you when hacking if you successfully hack an unaware enemy from behind.

As mentioned in the question, if you manage to pull this off, you are able to either directly control the machine lifeform you've hacked or simply turn them against their friends. It's also worth noting that if you choose to remotely control a machine lifeform, you can hack another machine lifeform and directly control that one, which means you can chain-hack your way through a group of enemies until you're in control of the one you want to control. This is especially useful if the machine lifeform you are controlling is near death -- you can simply switch to a healthier machine to keep on wreaking havoc.

Another important thing to note is that controlling a machine lifeform remotely is necessary for the trophy/achievement Machines vs. Machines, which requires you to kill 50 machine lifeforms while remotely controlling another machine lifeform.