Here is my take on this situation. This 'spotlighting' is someones 'very bad idea with good intentions.' You are NOT being petty! It sounds like someone came up with this bad idea thinking it would be a positive influence, but any kind of 'spotlighting' is wrong because it leads to children feeling either less than or more than no matter what is said!! There is no way around that. Whether the statement came from another kid or a teacher, it is wrong.
This spotlighting idea is truly psychologically flawed because it only can ever lead to divisiveness AND discrimination. No matter what is said, these things shape and influence a persons life!! This is no small matter.
I would be outraged and talk to the other mothers to stop this 'sharing of personal judgments' now. The teachers cannot be trusted to manage this anyway! There is no second chance after a comment like that.
I suggest you truly trust your own gut on this and not feel in any way apologetic for making a fuss over this incident and stand FIRM that this is totally unacceptable and needs to be stopped. NO 'spotlighting' because it is divisive and discriminatory, period!!
When you talk to the Principal you could acknowledge that while this appears to be an attempt at positive reinforcement, and you can see they are trying to 'be a positive influence,' the problem is that 'spotlighting' isn't a positive influence because it is only sharing PERSONAL OPINIONS AND JUDGMENTS and this creates divisiveness among children and is discrimination!!!
The teachers cannot be trusted with this kind of power- no matter what they say. No students comments should be passed on either. That is worse.
Imagine if this scenario where done in an adult office. The boss comes out and says, "John, I like your enthusiasm and I like having you in the office." The next day she says, " Jill you have THE BEST hair and are the COOLEST dresser." Announcing personal opinions and judgments is controlling, shaming, manipulating, insulting and totally discriminatory. A boss could be sued for that kind of "spotlighting" (discrimination!)
I only offer my opinion only here for what that is worth.
Good luck and follow your intuition, J.