The Camera form field allows the person filling out the form to add an image to their report, either by taking a photo with their device camera as they go, or by uploading an image that's already saved on the device. (See: How do I add a photo field into a Form Template?)
The Image form field is different, in that it is a static image that always appears in every new form that is created from the Form Template. It requires the form builder to select an image from their Formitize account's Resources. Once selected, that image will appear in every form of that type. (Resource Documents Overview).
Please note: The Image can be hidden in the form, by un-selecting the 'Visible' option in the Field Settings. You can then create an event with a multiple choice field, wherein a specific answer will allow the image to appear. (See: How do Form Events work?)