This is super deceiving and I'm kind of upset they posted this image, knowing it would mislead people not familiar with the game. The AI sits around during lulls at <30 APM - meanwhile MaNa and TLO were literally spamming keys to keep their fingers warm, not actually doing anything.
During the fights, the critical moments in when MaNa would top out at ~600 humanly inaccurate APM (this is 10 inputs per second), the AI would jump up to over 1000 - we don't know exactly what it was doing, but it was presumably pixel-precise. Meanwhile the physical inertia of the mouse is a challenge for humans at that speed - imagine trying to click five totally different places with perfect precision in a single second.
APM gets inflated by counting several single actions as multiple separate actions. For example a Zerg player may want to turn larva into 30 Zerglings, they do this by pressing one button and holding it down as the UI repeats a separate action for each larva transformed.
By comparison selecting a single stalker, and having it jump to a new location is much more effort, but counts as fewer actions.
During the fights, the critical moments in when MaNa would top out at ~600 humanly inaccurate APM (this is 10 inputs per second), the AI would jump up to over 1000 - we don't know exactly what it was doing, but it was presumably pixel-precise. Meanwhile the physical inertia of the mouse is a challenge for humans at that speed - imagine trying to click five totally different places with perfect precision in a single second.