Good overview of it, but those polyfills are so pointless. By the time you load the two separate fills for IE11 (meaning two extra handshakes), and run them, the page could probably have just loaded the images normally.
But as I've said for some time, people would probably stop diving for the goofy tricks and stupid scripting stunts if they would just stop wasting 100k of markup on 16k's job, 500k of CSS in a half dozen files on 48k or less in 1 files job, and multiple megabytes of scripttardery in dozens of separate files on pages that likely don't need more than 64k of JS (IF ANY?!?) in one file.
All these excess polyfills being a contributor to this. At that point, just let things gracefully degrade! I'm oft amazed at the hoops people will jump through just to make a few fancy bells and whistles work in outdated browsers.