Hello @maxwellmarcusart. Nice pen shading. The concept at Pinterest also applies to Facebook. If you posted your personal photos and artwork to those sites, would you want others to copy and use them without your permission? Just placing a link to the image doesn't guarantee it's free to use, remember. Perhaps this image has a different copyright usage since the person you mention is a public figure and placed his photo on Facebook. Did you check first?

I don't use Facebook, so I can't check.

Also, if you use an image as reference and it's free to use, then place the image and its link in your post so that your readers can see how well your interpretation looks compared to the real photo. Just like you do in Splinterlands and Holorizing.

Take care.