If you want to use an image in Xamarin.Forms you have to use a differnt path or name for each plaftorm.
This may make the xaml file difficult to read, because you have to add platform specfic code in XAML like this:
Instead of those lines of code, you can also use a marukup extension which merge the image for you. This means, you have to add the name of the image in XAML. The rest of the path, will be added with this markup extension.
This makes it easier and more readable for the developers.
You can have a look on it in my github repository:
AustrianCoding 