If you own an Apple TV and you're not using AirPlay, you're missing out! You can easily see pictures and videos on your iDevice on your TV screen with just a few taps.
First, make sure your iPhone or iPad is on the same Wi-Fi network as your Apple TV.
Next, bring up Control Center on your iDevice and tap AirPlay and then Apple TV. Slide Mirroring to the On position in order to see your content on both screens.
You can also share content directly from Music, Safari, Netflix, Video, YouTube, Pandora, many iOS games, or any other AirPlay-enabled app.