Downloaded Images Not Showing Up in Android App

Hi everyone! I'm working on my first Xamarin.Forms app and I'm trying to display a downloaded image in accordance with this document:

developer.xamarin.com/guides/cross-platform/xamarin-forms/working-with/images/#Downloading_Images

And the downloaded image shows up great on the Windows phone emulator, but on the Android emulator the downloaded image is not displayed. What am I doing wrong?

Thanks in advance for your help!