The ms-appx protocol references images that are included in the .appx package. If localized, scaled, and high contrast resources are provided, the correct asset will be automatically displayed.
The ms-appdata protocol references images that are saved to the storage folder (Windows.Storage.ApplicationData.current.localFolder)
The http and https protocol will download web images.
Web images can be appended with query strings so that localized, scaled, and high
contrast images can be returned by the web server if desired.
A baseUri can be specified in a notification for web images. The incomplete baseUri
will be combined with the relative image path to form a complete absolute path.