1. An image adjustment method, comprising: providing an electronic device having a front-facing image capturing device and a front-facing display device; displaying a display content by the display device, wherein the display content is not an original image captured by the image capturing device; capturing, with the image capturing device, a user image of a user while using the electronic device; identifying a facial feature location of the user according to the user image; determining a vertical skew angle of the electronic device relative to the user according to the facial feature location; elongating the display content into a deformed image according to the vertical skew angle, wherein the deformed image is an elongated image; and displaying the deformed image by the display device.