The figures are so tiny they're unreadable, and the contrast (black on colour) is poor too - I can only just make out that there's a character there, which I'm ''guessing'' is a figure. When we first got the icons, the contrast was good, as it used white figures on a dark-coloured background, and the figures were large compared to the links at either side - I think they were boldfaced too. I could fix this by working out the CSS rules ([//meta.wikimedia.org/w/index.php?title=User:Redrose64/global.css&action=history&offset=20160804223000&limit=5 yet again]) that would make it readable for me, but I shouldn't need to. This is an accessibility issue.
We made the font size of these numbers 8px in Monobook when we scaled down the Vector one, but we could just use the same font size that Vector uses despite the fact that everything else is smaller in Monobook.