Constraints of different browsers
Is your website attractive, well laid out, fast to load and easily navigable? Can a user find the information he needs with just 3 clicks? Design for the Web needs to be focused, relevant and crisp since it is bound by so many other constraints. Constraints of different browsers, different screen resolutions and different bandwidth all come into play. The same design can look disastrously different in different situations.
So next time when you visit any developing office , be sure to ask them for testing of your website.