You can configure the properties of the Thumbnail element in the Properties panel on the right sidebar.
Value: You can add a static value or dynamically retrieve a state, the content of the Thumbnail element or the value obtained as a result of an action via Symbol Picker.
Placeholder Image: The image shown when there is no image value. If no content is loaded, this image is displayed instead of an empty space.
Zoom On Click: When the user clicks on the thumbnail, a larger version of the image is displayed. When the switch is activated, the small preview changes to a full-size image.
Image Fit: Determines how the image will scale to the dimensions specified in the Styling > Layout tab or the dimensions of the parent element.
Position: Determines the position of the image to be displayed. You can choose between the following options from the drop-down menu: