To view pictures and videos stored in iCloud, you can follow these steps:

1. Open a web browser and go to https://icloud.com.
2. Log in with your Apple ID.
3. Click on the Photos icon.
4. You will now see all the photos and videos stored on your iCloud account. Alternatively, you can open the Photos app on your device and tap on the Library tab to see your photos. If you want to view a photo or video full screen, double-click a thumbnail. If you don't see iCloud Photos, click Pictures in the Navigation pane, then double-click iCloud Photos.