Hi Quim and Pau,
TL;DR, the suggested design icons are men.
I realize that it's not the best to make a negative comment without
offering a solution, but here I go. Both of these suggestions for the
design icon read as men (the first even being called "man" that refers to
mankind most likely but no one ever thinks of a woman, and the second being
a fairly stereotypical architect bald-with-glasses look which I suppose
could sort be a generic person but doesn't read as anything other than a
man to me, personally).
While I know that you have no intention to imply anything in that regard,
if I were approaching as a volunteer and a woman it would (maybe only
subconsciously) read to me as if things are a bit man-centric.
I would prefer that not be the case.
Regarding the design icon I would prefer something more simplistic.
seem to be based on the noun project, I took the architect
this quick adaptation
make it a bit more MediaWiki specific (and replace #000 with #111). I
made a screenshot of the result in the page
see the icon in context.
Looks good. Can you upload the icon to Commons, please?