Actual, the categories are simply a collapsible content/header construct, which isn't (maybe) the best design for it.
Jon suggested (in this bug: https://gerrit.wikimedia.org/r/#/c/170431) to convert this into a categories button (like the "lnaguages" button), and i support this idea :) This bug should track work and discussion on this. Opinions? :-)
Version: unspecified
Severity: enhancement