The length of time required for a page to load useful information is reasonable.Courtesy is similar to but different enough from clarity that it warrants special consideration.
Inline images enhance the initial presentation, but can significantly slow down the display of the page. The adage "form follows function" is now "form follows function as a function of time." The size of pages, as well as images and other presentation enhancements, is both dimensional size (width and height) and file size (bytes). A good presentation can be seen negatively by the viewing audience if the time for the page to appear is too long.