The way the graphs work is, you have piston travel speed plotted on the left, and resistance to movement plotted along the bottom axis. You have a horizontal line across the middle, which crosses the left axis at the point of zero shaft movement. Above that line, the axis charts shaft speed in the rebound (extension) direction, below the line, it charts shaft speed in the bump (compression) direction.
There's a couple things to know about shaft speed and direction. First, shocks and struts (which I'll call by their proper name "dampers" from here on) shouldn't necessarily be providing the same levels of damping in both directions. In compression, they're working with the springs, and in rebound, the springs are working against them trying to shove the wheel assembly down. So usually, a damper will have less resistance (damping) in the compression direction and more in the rebound direction. And it's rebound that provides most of what we try to get out of a damper from a tuning perspective.
Secondly, shaft speed. We usually refer to this as "low speed" vs "high speed", the terms being relative, of course. Low speed is the speeds the shaft is likely to be moving when the car transitions into a corner, or dives under braking, that kind of thing. High speed is what it sees when it hits a bump or a pothole.
The trick is to get the damper to control the wheel properly at high speeds without making it immobile at low speeds, and on the flip side, to provide proper control at low shaft speeds without being a wet noodle at high shaft speeds.
So you'll notice the curves are non-linear. At low shaft speeds, damping builds at a certain rate, then as shaft speed reached a certain point, the damping builds at a different rate.
This presentation is getting old now but you'll see what I mean, hopefully. Bear in mind it looks like they reversed the adjustment numbers on the Tokico graphs.