Instagram on Windows Phone lacks many of the features found in the iOS and Android apps, but its design is pretty much the same. The main screen shows a feed (above) of all the photos and video the people you follow have posted, in reverse chronological order.
You can't shoot videos with Instagram for Windows Phone, but videos that others post will show up and play in your feed. You can easily spot videos by looking for the play icon in the top-right corner. In the other apps, if you leave a video in view on the screen for a few seconds (depending on your connection), the video will load and automatically play once. Here, you must tap the video to start playing it.