I realized some logos aren't optimalized. I'm running optipng -o7 at all of them to be sure all of them are optimalized (as optipng do nothing where nothing to optimalize).
The new files are on Wikimedia server but I have not deployed them yet. There is an ongoing issue with thumbnails so I would rather not mess with that right now. Will deploy the new project-logos once solved.
It really shouldn't be related to this deploy as a) cywiki's logos wasn't even touched by this change b) correct logos are on the server, see en.wikipedia.org/static/images/project-logos/cywiki.png, en.wikipedia.org/static/images/project-logos/cywiki-1.5x.png and en.wikipedia.org/static/images/project-logos/cywiki-2x.png...