Now Playing: Alicia Silverstone remembers 'Clueless' co-star Brittany Murphy's audition

Now Playing: The Obamas ink a multiyear deal with Netflix

Now Playing: 'GMA' Hot List: The choir director from the royal wedding speaks out

Now Playing: 'Clueless' star Alicia Silverstone on trying 63 different outfits for the movie

Now Playing: Stars walk Billboard Music Awards red carpet

Now Playing: Chrissy Teigen shares 1st photo of baby boy

Now Playing: Ed Sheeran, Kendrick Lamar win big at Billboard awards

Now Playing: The cast of 'Arrested Development' dishes on Season 5

Now Playing: The best moments from the Billboard Music Awards

Now Playing: Elton John takes final bow of Las Vegas residency at Caesars Palace

Now Playing: Royal wedding watched by more than 29M US viewers

Now Playing: Kelly Clarkson calls for action in response to school shootings at Billboard Awards

Now Playing: Exclusive sneak peek of the 'Roseanne' season finale

Now Playing: A look inside the world famous Kew Gardens

Now Playing: The unofficial colors of the royal wedding? Spring-inspired blue and green!

Now Playing: Harry and Meghan's royal wedding sermon was an uplifting message of hope and love

Now Playing: Royal Wedding Rewind: watch every can't-miss moment from Harry and Meghan's big day

Now Playing: Meghan Markle has changed bridal style with her unforgettable Givenchy custom dress

Now Playing: These adorable royal wedding kid guests made us smile

Now Playing: These royal wedding dresses changed fashion history