The new link drag images fit well with macOS High Sierra, because the OS gives them a drop shadow that separates them from white backgrounds. In Sierra and El Capitan, there is no shadow, so the images blend into white backgrounds.
<rdar://problem/32580649>
Created attachment 312572 [details] Add a drop shadow
Created attachment 312573 [details] Add a drop shadow
Comment on attachment 312573 [details] Add a drop shadow Clearing flags on attachment: 312573 Committed r218052: <http://trac.webkit.org/changeset/218052>
All reviewed patches have been landed. Closing bug.