Hi XamS,
Greetings from Syncfusion.
We would like to inform you that, we rendered Annotation with its initially measured size since it is just used to mark the specific area in the gauge with a custom view like label, shape, image, etc., So, if you change the property value’s in the view, we cannot get the notification in source level (view can be anything like label or image or any other view) in order to re-measure the size of view based on changed value. If the image size is needed to change dynamically then, create a new instance for the image with a different size and replace it with the annotation view.
Regards,
Eswaran