User blog comment:DaNASCAT/Technical Update: January 6, 2016/@comment-1824272-20160107132130/@comment-452-20160107175256

.page-Special_NewFiles img.thumbimage { margin-left: 0 !important; width: 212px; }

Unfortunately, they now specify set rows of 4, instead of allowing the thumbs to automatically flow to the width of the page.