<DataTemplate x:Key="PhotoTemplate"
                          DataType="{x:Type l:Photo}">
                <Button Command="{Binding OpenPhotoCommand}">
                    <Button.Template>
                        <ControlTemplate>
                            <Image Margin="0,10"
                                   Source="{Binding Source}"
                                   MaxHeight="300"
                                   MaxWidth="300"
                                   Width="{Binding ExpectedWidth}"
                                   Height="{Binding ExpectedHeight}"
                                   Stretch="Uniform"
                                   x:Name="Image"
                                   RenderOptions.BitmapScalingMode="HighQuality"/>
                        </ControlTemplate>
                    </Button.Template>
                </Button>
            </DataTemplate>