It’s really difficult to say with a naked eye whether an image is original or manipulated one, thanks to Adobe Photoshop for this. Is your friend send a photo which you want to know whether is edited with Photoshop or not, is this possible? yes isEdited.com site tells you whether your uploaded JEPG image is photoshoped or not.
Just upload the JPEG photo with less than 2MB size at isEdited.com, with in seconds this site tells photo is edited with Photoshop or not. isEdited.com can say this with, whether photo was exported using Photoshop or not.