Hi there sir,
The theme has no such feature for image preview & we didn’t showcase anything that the image or file upload will show a preview, so I think it’s not against any rules or it’s not that the theme is not working for that. I think if you want to show preview of the image you may want to customize it so that it shows preview when choosing. You can use several library which are open source. By the way it’d be a nice feature to have though we’ll try to add this feature in near future.