Well, this is quirky. :)

So in a StackLayoutI had an embedded StackLayout:

        <StackLayout x:Name="slActivity" Orientation ="Horizontal" IsVisible="false" >
            <ActivityIndicator x:Name="actSpinner" />
            <Label x:Name="lblLoading" Text="Loading..." Font="Bold" />
        </StackLayout>

Now, in my code, obviously when I need that to show I would set the slActivity.IsVisible to true, and set the actSpinner.IsRunning to true. When the activity finishes, I set both back to false.

Only, when I tested my app on the Android simulator, I was only seeing my ActivityIndicator, and not the Label. I couldn't understand why...as it turns out, I didn't set the StackLayoutto visible, I set the ActivityIndicatorto visible. A simple mistake, simple to fix...

...but why did the ActivityIndicator show up if the StackLayout that contains it was still set to not be visible??