Can you present an image without knowing who originally created it?
Best Case Scenario: As one commented, you can use reverse image search on Google; or just use other search engines and see who created it. If you find it, then you can use the link to the original artist as a reference.

Worst Case Scenario: The good thing is that there is a link for it! So if you couldn't find the graphical artist (the worst case scenario) add the picture and its reference (its related link) in the slide's footnote. To be on the safe side, use the popular link (one of the links on the first page).