Is it OK to put that picture on your class website? Are you legally allowed to use a specific photo in your PowerPoint presentation? Check out the link below to a good explanation of fair use in education.
Fair use summary: http://fairuse.stanford.edu/overview/fair-use/four-factors/
Fair use in presentations: http://fairuse.stanford.edu/overview/academic-and-educational-permissions/proposed-fair-use-guidelines/
