Its my picture.
The goal of any valve train, as far as I'm concerned, is to perfectly follow the motion imparted by the cam lobes. The rocker arm geometry as I have drawn it makes no attempt to optimize geometry at the push rod cup; but it optimizes geometry at the valve tip. By optimum geometry I mean: (1) motion at the rocker arm tip shall be most linear, (2) side thrust between the valve stem and valve guide is minimized, (3) valve guide wear is therefore minimized too, (4) the width of the rocker arm tip's wear pattern across the tip of the valve is also minimized, and (5) valve motion imparted by rocker tip motion is maximized. The geometry as I have drawn it may not achieve the most overall valve motion (valve travel), that will depend completely on how well the rocker arm is designed (the angle of the push rod cup in relation to the rocker arm body). However, I feel in a street application the priority should be (1) high mileage durability and (2) maximizing performance … perhaps just the opposite of what the builder of a race engine may prioritize.
There are several "theories" regarding rocker arm geometry. Frankly the rocker arm instructions provided by some of the cam companies is the worst! Jim Miller's is OK. I've seen the "fulcrum line or motion line" explained as per the pictures you posted many times over the years, but with due respect to the author it is geometrically wrong. What I've drawn is correct.
There are two aspects this rocker arm geometry doesn't accomplish: (1) geometry between the rocker arm and push rod is not optimized, it relies on the design of the rocker arm to be reasonably "accurate". (2) Nothing has been done to center the rocker arm's contact patch on the valve tip.
The "ball end" design of push rods makes geometry between the rocker arm's push rod cup and the push rod less critical. Less than perfect geometry at that end will not result in the accelerated wear that poor geometry at the other end does.
To set the geometry requires adjusting the height of each rocker arm and adjusting the lateral distance between each rocker arm and the associated valve. Adjusting all 16 rocker arms individually is time consuming; but its not too difficult with the head sitting on a work bench. This type of rocker arm makes that possible.