If you go into settings- Display - Daydream you should have some options of apps to activate. You can select Sony's SensMe or if installed you can have it display Google Currents which depending on what you subscribe to would show news and articles.
Other Apps that can use Daydream mode include Flipboard, Weather Daydream Screensaver, Zoum Twitter Daydream. There are also a bunch of clocks. Google "Android daydream app" and you should find them all.
You can also chose either charging.Docked or both to activate it.