Brooklyn-based start up MikMak has an app that is part QVC, part Snapchat: It creates 30-second shopping videos for phone-obsessed millennials. MikMak founder Rachel Tipograph joins Tanya Rivero to discuss. Photo: Adrienne Grunwald for The Wall Street Journal Subscribe to the WSJ channel here: More from the Wall Street Journal: Visit WSJ.com: Follow WSJ on Facebook: Follow WSJ on Google+: https://plus.google.com/+wsj/posts Follow WSJ on Twitter: https://twitter.com/WSJvideo Follow WSJ on Instagram: Follow WSJ on Pinterest: Don’t miss a WSJ video, subscribe here: More from the Wall Street Journal: Visit WSJ.com: Vis