When they say “computer”, they don’t mean a laptop. They mean a cycling computer, a little gizmo that tracks your speed, distance, pedaling cadence, grade, climbing distance, and maybe heart rate. In the cycling world these days, if you didn’t log the ride, you didn’t do the ride :)
I'm not all that deep into the bikepacking/touring world (just some weekend rides) but it's not something I see referenced, however they have some pretty amazing storage and packing options that remind me of it:
Pannier bags are the go-to design for both bicycles and motorcycles, for good reason.
They keep weight off your back and the center of gravity as low as possible. They also don't interfere with swinging your leg over the bike, unlike rear baskets or top boxes.
When properly attached, you don't really notice them at all, other than making your bike a bit heavier up hills.
I DIYed my own pannier bags from military surplus shoulder bags. They're not pretty, but then again neither is my bike.
Handlebar bags are more of a bonus item, you use it for things you need to grab while riding, small snacks and that sort of thing.
As an outsider peering in, this reminds me of that book, given its a way to mount your laptop and everything else to your bike.