I found this while poking around on t.msn.com. FYI - that site only was reachable from IE on my Windows 8 VM.

<meta name="application-name" content="MSN for Windows 8"/>
<meta name="msapplication-TileColor" content="#007eb0"/>
<meta name="msapplication-TileImage" content="/content/images/MSNButterfly.png"/> 

This looks like specific code for putting a webapp into the start menu in the Windows 8 Modern UI.