Image control doesn't support Tilt effect. But You can put it to other tiltable controls such StackPanel, Grid, Border and so on. For instance I am putting it to StackPanel.
<StackPanel toolkit:TiltEffect.IsTiltEnabled="True">
<Image Height="100" Name="imagePlay" Stretch="UniformToFill" VerticalAlignment="Center" Width="100" toolkit:TiltEffect.IsTiltEnabled="True" Source="/Music%20Player%20Pro;component/Images/Play.White.png" Margin="20,0,0,0" Tap="imagePlay_Tap" />
</StackPanel>
By default StackPanel is not tiltable and you must add StackPanel type to TiltableItems like that in the page constructor.
public MainPage()
{
InitializeComponent();
TiltEffect.TiltableItems.Add(typeof(StackPanel));
}