Nexus 10 ActionSheet looks like dialog not ActionSheet. Is this a bug?

on Nexus 10 I am displaying an ActionSheet like so:

_page.DisplayActionSheet(title, cancel, destruction, buttons.Select(x => x.Value).ToArray());

and according to this page: http://developer.xamarin.com/guides/cross-platform/xamarin-forms/working-with/pop-ups/

Should look like so:

But mine looks like a DialogBox.

Is this a bug