The lowsrc attribute is used to attach a second URL to an
element. The URL identifies an image similar to the one indicated by the src attribute but in low-resolution format.
- The image indicated by src and lowsrc can be different images.
- The low-resolution image (indicated by the lowsrc attribute) will be downloaded first (useful for low-speed connections) and later the actual image (sr attribute) will be downloaded.
- It is recommended to use the same size for both images to avoid flicking of image during download of high resolution image.