You don’t even have to ask for permission if you do it in a way that people can get to the author’s original content. And yes, as long as you are embedding it’s completely legal. Hope my answer is helpful! Is it legal to take photos of people in public (who request) and then sell the photos to them?
What Sells Best On Shutterstock?
Some types of photos that sell best are Portrait Photography, Food Photography, Landscapes (usually with people) and fine art photography (artsy).