Here (en (dot) swordofmoonlight (dot) org/wiki/Sword_of_Moonlight/installing) is a page with a slideshow gallery (1.33.1) that creates explosive images on both Firefox and Google Chrome. Firefox sometimes corrects the size somehow, but Chrome is best at seeing the effect. The PNG files involved might be irregular or something... it's certainly odd. I can't imagine this is expected behavior.
Topic on Project:Support desk
Too on that page I'm having a problem with OOUI icons not generating that I put here (Topic:Vcpe72p0ltqwz2yd) alongside someone's question that was answered. I'm not sure that's the best venue. I used CSS to insert the triangles that are all that are serving as buttons to move along the slideshow ATM.