Break down Traffic Sources by Mobile in v15

[#1]

For some reason I can break down Mobile (Manufacturer, for example) Reports by Traffic Sources (Referring Domain, Original Referring Domain, Search) but not vice versa. Wouldn't it make sense to have this go both ways?

[#2]

Have the exact same problem with eVars and Pagename. Why can I break down Mobile by eVars and Pagename, but not vice versa? Arg!

All I want to see is what mobile devices are accessing a specific page. Seems easy enough to me...