Rotation: This value stands for the rotation angle of the image element.
Change button: This button is used to change the source file of the image.
Maintain Aspect Ratio: Check this checkbox, when you change the image size, the aspect of the image will stay.
Thickness: This option controls the border thickness of the image element
Border color: This option controls the border color of the image element.
Corner Radius: By adjusting this value, the sharp corner of image element will turn round.
Loader Size: You can change the loader radius size by modifying this value, while the image is being load, loader will be displayed to indicate loading progress.
Tickwidth: You can change this value to modify the tick width of your image loader.
Loader color: Change the color of your loader

Special option for image element: image can be displayed in full-screen mode when you check the "Full Screen" checkbox in the layout tab of image element's property panel.