To address your specific requirements, one approach is to define minimum width and height attributes in the css rather than just specifying width. By doing so, the element will adjust to the necessary dimensions and can be fixed to the top left corner (note that any overflow on the right side will be cropped).
For more insights, check out:
http://css-tricks.com/perfect-full-page-background-image/
Here's a more detailed explanation of the issue at hand:
When setting an image to 100% width within its container without indicating a height, it will be stretched until it completely fills the container, while the height adjusts to maintain the image's original aspect ratio.
For example: If you have an image sized 200px x 100px and place it in a 300px wide container with its width set to 100%, it will be scaled by a factor of 300/200 = 1.5 in both dimensions, resulting in a final size of 300px x 150px.
However, if the image's aspect ratio differs from the user's screen, it will stretch to fill the full width and leave the remaining area blank. Adding a specified height may cause further distortion issues as the image tries to adjust accordingly.