So, I tinkered with this a bit yesterday. What you probably want is something more like an EventTrigger. I did this on MouseUp, but I guess for your usage it would be TouchUp. I also used the event to reset the placement target since it seemed to break doing this. As far as how you want it to look, you might want to check out
ToolTip Styles and Templates[
^].
<Image Name="testimage" Source="silhouette.jpg" Height="57" Width="100" MouseUp="MouseUp_setTarget">
<Image.ToolTip>
<ToolTip PlacementTarget="{Binding ElementName=testimage}" Placement="Right">
private void MouseUp_setTarget(object sender, MouseButtonEventArgs e)
{
((ToolTip)(((FrameworkElement)sender).ToolTip)).PlacementTarget = ((FrameworkElement)sender);
}
<Image.Triggers>
<EventTrigger RoutedEvent="MouseUp">
<BeginStoryboard>
<Storyboard>
<BooleanAnimationUsingKeyFrames Storyboard.TargetName="{x:Null}" Storyboard.TargetProperty="ToolTip.IsOpen">
<DiscreteBooleanKeyFrame KeyTime="0:0:0" Value="True" />
<DiscreteBooleanKeyFrame KeyTime="0:0:5" Value="False" />
</BooleanAnimationUsingKeyFrames>
</Storyboard>
</BeginStoryboard>
</EventTrigger>
</Image.Triggers>