Much more important is what is the source of photo, what and where was the event, who was holding the lecture etc. All that might give some hints about credibility.
If there is credibility to the graphic, then that might infer the pl-16 is more likely to be a full sized, pl-15 sized, missile. Just with clipped/folded/rearranged fins. Instead of some narrow body whole new design concept missile.
Technically speaking one can be a full sized, PL-15 sized missile while also being a narrow body new design concept missile, after all PL-15 (and PL-12) have the same fuselage diameter.
Given PL-16 is meant to be allow J-20 to accommodate six internally, a slightly narrower fuselage diameter and a smaller fin footprint, combined with newer guidance systems and flight control laws, newer materials, newer propulsion, newer warhead design (aka things to reduce weight, while enhancing flight efficiency and enhancing propulsion) could still fulfill the criteria of "narrower/smaller footprint than PL-15 but having better performance than current PL-15".
However I agree that the photo is sus and needs to be taken with generous amounts of salt.
I am reading it as 0 for head-on, 180 for tail chase.
Shouldn't it be the other way around?
180 degrees should be the engagement envelope for a head on engagement, while 0 degrees should be the engagement envelope for a tail chase.
The engagement envelope for a head on engagement for a AAM should be the highest value, while the engagement envelope for a tail chase engagement should be the lowest value.