"Setting up a Photowall is easy. You'll need to have a Chromecast plugged into your TV, then you can create a Photowall from your laptop, phone or tablet. Once you're set up, you and your friends can start sending photos directly to the big screen. When you're finished, a YouTube video of your Photowall is automatically generated, which is perfect for sharing with everyone who took part," explains Google. Photowall works even if you don't have a Chromecast: it will use your computer screen.
Google also developed apps for Android and iOS. You can also upload photos from your favorite mobile browser by visiting g.co/photowall. Google even lets you tweak the photo before sending it to the TV: you can crop it, add captions and draw using the "doodle" feature.