Nope, the browser calculates the size for the images and reserves the space on the page until it is fully down loaded and displays a placeholder until the full image is downloaded and ready for display. Once I viewed the page, I have the image in my cache and a reload or refresh occurs instantly because it is locally available on my machine. All this is normal operation.
There are places on the web that will measure all the compnents on the page you supply an URL for and issue a report on the page listing information such as the number and size of images and other objects on the page and they supply pretty good reccomendations for improvinging the load times.
here is one such site.