Include the height and width of the graphic to make pages load evenly. When heights and widths are not set within image tags, pages mutate as information is pushed to the side to make way for loading pictures.
Graphics can be large files. Due to connection speeds to the Internet, the amount of information on a page must be kept to a minimum so that users do not become frustrated as they wait for pages to load. Files must be reduced in size. Either reduce the physical size of the image by making the height and width smaller or save the file at a lower resolution so the file will contain less information.