I am not sure I understand correctly your request. The images are not acting like a carousel they are not changed until a thumbnail is clicked.
The widget template can not be edited to automatically change the image after a period of time as it is using RadListView to display them and RadListView does not have such property.
There is an image rotator widget availabel in the marketplace
. you can check if it suits your needs.
Also you may take a look at the example of NewsRotator
which relies on RadRotator to rotate images from an album.
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