Unlike the conventional File Upload element, Image Upload is designed to cater to images. Images uploaded will be displayed depending on the dimension set.
Figure 1: Image Upload
The above screenshot is taken from the modified Account Form found in the CRM application.
Figure 2: Properties of Image Upload
ID: ID of the element
Label: Label of the element
Readonly: Determines if this element is editable
Width(px): Maximum width of the displayed image
Height(px): Maximum height of the displayed image
Create Thumbnail?: Generates thumbnail 
Validator: Conventional validator
Maximum File Size (KB): File size limit for the photo uploaded
Error Message (File size limit exceeded): Message to be displayed when file size limit exceeded
Image File Type: File extension(s) allowed
Error Message (File type mismatch): Message to be displayed when file type mismatch