Answer:
One possible problem is layout of the website which fit a desktop machine doesn't fit well on a mobile screen. The problem can be worsened by a variety size of the mobile screens that there is no single and fixed layout can be applied to all types of the screens. The layout presentation may be rendered inconsistently across different mobile screen. This is better to have a earlier planning to work out a responsive design that works for different screen before starting to develop the desktop website.
