What are those gems on the new Changeling design?

I know the fandom (at least on this website) has some pretty mixed feelings about the new Changeling design, I personally don’t mind it at all. But what intrigues me the most about them are those three gems planted on their neck region.  
 
Anyone wanna throw out their own theory on what purpose they could possibly serve?

Kinda curious about them myself. Especially given that only some of them have the gems, not all.
 

@Zeb  
My first theory is that they’re an emblem/symbol to recognize and/or give honor to the Crystal Empire considering the fact that Thorax has some kind of relation with them; could’ve been the effects of the crystal heart had on the guy. Also his wings did have a crystalline look to them before transformation too.

@Tazool  
True. Though that doesn’t account for the other changeling who have gems.
 
I remember seeing a few theories that they could represent gender. But unless we hear more of them speak, that’s just a guess.
 
Could be a subtle class difference. Like working class/warrior class/infiltrator class. Kinda like earth pony, pegasus, unicorn. Slight differences within the race, only now that they’re “fully grown” the differences are far more noticeable.

@Zeb  
To be honest, I’ll agree more with your idea as it certainly makes a lot more sense to have an indicator to let other Changelings know what role or position they are in the hive. All of them have basically the same body structure w/slight variations to color, horn, and gem thingies; it can get chaotic when you have hundreds of thousands of Changelings in a single hive, and not having any reliable methods to identify which is which.