"most helpful" reviews order

Anyone know how the "most helpful" customer reviews ordering works on the new iOS App Store?

On iTunesConnect, under an iOS app's reviews and ratings tab, you can see some sort of "helpful rating" (ie "1 of 3 viewers found this review helpful"). However, this doesn't seem to match the position of the review when using the "most helpful" ordering (which is the only option on iOS11).

Is Apple using other metrics that aren't visible in iTC? Is this ordering broken right now? It seems to be.