Jenny Slate, star of the upcoming film "Landline," answers questions about 21st century phone etiquette. From questions about your crush not adding you on Snapchat to how to make a collect call, Jenny handles it all. "Landline" debuts in theaters on July 21st. br br #LandlineMovie br br br Still haven’t subscribed to Vanity Fair on YouTube? ►► br br ABOUT VANITY FAIR br Arts and entertainment, business and media, politics, and world affairs—Vanity Fair’s features and exclusive videos capture the people, places, and ideas that define modern culture.