The existing source is good enough, no need to link to it too.
Frankly, it isn't. The actual link should be link to, directly, not just a title you can use to find from a third-party. The actual source the image was taken from should be linked to.
This is akin to if a music video were uploaded, making the source the title of the video, rather than linking directly to the YouTube video, we should always use direct links to the content where something is sourced from, with titles such as the current source being as supplemental source information.
