This is a mystery I’ve been wondering about for a while now, and I’ve never been able to come up with an answer. A few years back, WordPress introduced a feature in the browser version of the Reader where if you hover the mouse over the “like” button, you’ll see who has already liked a post. I don’t like that feature, but that’s beside the point. The mystery is the order in which WP displays who has liked a post, because it’s not chronological (as opposed to the order in which you see your notifications under the little bell thing, which is chronological).
No matter whose post it is, if Paula, Suzette, and I have all liked a particular post, Paula’s name will always show up higher than my name in the little pop-up list of likers, and my name will always show up higher than Suzette’s. If we throw Maja of Lampelina into the mix, her name will always be higher than Paula’s, Suzette’s, and mine. Again, this order is consistent, no matter whose post it is that’s been liked. I’m assuming that the order I see is the same order that other people see when looking at the Reader, but I don’t actually know that for sure; it’s certainly possible that other people see an entirely different order.
If there is a consistent order, and it’s not chronological or alphabetical, what on earth is it? Any ideas?
Update: Mystery solved! The info about who likes a post comes from the WordPress REST API, which returns a list of who’s liked a post ordered by user ID number (yup, you’ve got one of those). That’s why Paula’s always above me and I’m always above Suzette. I have no idea if that ID number is based on something (like maybe when you first created a WordPress.com account), but the order of likers is based on that number.