The Ortofon 2M blue picture shows nothing useful. It's just a blurry blob photo.
We (my father in his collection and mine) have literally many hundreds of cartridges and many more styli of all different ages, pedigrees and use. He has been looking at styli under his medical microscope since before I was born and he's 90 now. I look at mine under both an electronic 'scope and an Olympus optical scope.
I have never seen 'wear' like that supposed 2M shot. It is likely just internal reflections and/or shadows. Styli are not polished like a diamond ring. You get some clear ones, particularly with say the likes of Shure's MR or some nice Japanese high end MMs and MCs, but the majority are just a dull stones, when they are new and remain so all their life.
It's easy to photograph or 'see' wear on a brand new stylus simply by illuminating it to show what you want.
Now, on to record wear caused by a worn stylus which you brought up. This is another area where there is little to no actual evidence. What specifically (with evidence please) does a worn stylus do to a record to cause wear? How can anyone demonstrate the same stylus on the same record worn and not? They can't. As an aggressive profile wears, it becomes less aggressive and in turn less damaging to the groove. The contact patch widens, forces are more distributed and diminished. Sure, the electrical performance of the cartridge as a whole may diminish somewhat, but actual record damage? I don't believe it when all other factors remain the same.
A hyper elliptical must cause more groove damage than a conical as the contact 'patch' is less and the forces greater on the groove walls for the same tracking force.
Well, you need to know what you are looking for in order to see the wear. Most folks don't realize how small the contact patches actually are, and miss them even when looking directly at them! Lighting is also super critical, as diamond is a difficult subject to view and photograph.
That 2M Blue has ~500 hours of play time, and is pretty well-worn. A new 2M Blue has a "minor" radius of 0.3mil/8um, implying it will form a flat contact patch length of ~0.4mil/11um after ~100 hours or so of play. The 2M image above shows a contact patch length of 0.5mil/13um.
You are correct that "wear" can be mimicked by poor lighting. I've been fooled by this, and had to develop lighting systems and analysis techniques that would discriminate true versus phantom wear. I show a diagram above that is one aspect of this, and the composite view shown in first post is another aspect. True wear is most difficult to distinguish early in the stylus life, but later (like the 2M Blue) it is much easier.
Record wear is still a mystery to me. I brought it up since it often comes up in forum discussions, with folks worrying that their worn stylus is causing record damage. I've seen SEM photos of grooves with damage from playing, but I've never seen a scientific study to show wear vs hours of play or condition of stylus, let alone effect of stylus type. I can't agree with your statement about hyperellipticals causing more damage, as I don't know of any data to show the effect of one stylus type vs another.
