Twitter has spent its entire existence, especially since becoming a public company, in the shadow of Facebook. So maybe it shouldn’t come as a shock that someone asked Facebook CEO Mark Zuckerberg what he would do if he was CEO of Twitter, which has suffered stalled user growth and a slumping stock price in recent months.

Zuckerberg fielded the question at a town hall Q&A session in Berlin, according to VentureBeat. Though he initially said he didn’t know how to answer the question, he eventually pivoted to crow about Facebook’s own successes, especially the rapid growth of Instagram. The photo-sharing network is similar to Twitter TWTR in that many people flock to it in order to keep up with public figures, according to Zuckerberg. But Instagram has now exceeded Twitter by many major metrics. Instagram has more than 400 million users compared to Twitter’s 320 million and it has 200,000 advertisers compared to Twitter’s 130,000.

The next big development in this relationship between public figures and their followers will be live broadcasting, Zuckerberg predicts. Facebook FB has been heavily pushing live video and is now rolling out live-streaming to its Android users. Twitter, meanwhile, bought the live-streaming app Periscope in March.

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“‘Live’ is going to be an awesome thing for public figures… imagine your favorite public figure or politician having the power to broadcast from their pocket, go live, have an audience of thousands of people,” Zuckerberg said. “I think you’re going to see a lot of that on Instagram and Facebook, and if the Twitter folks do a good job, I think you’ll see a lot more of that on Twitter too.”

The challenge for Twitter, of course, will be to figure out how to effectively fit live video into the core user experience before Zuckerberg and his employees do.

This article was originally published on Time.com