You can upload photos/videos from the Add tab.
Tap the Add tab at the bottom of the screen, then select the photos/videos you'd like to upload.
Grandparents and other relatives can upload if an Album Admin (parent member) has turned on "Allow Album Member Uploads" in the Settings tab.
With Premium Family or Premium Family Pro, you also have the option of uploading photos and videos from your computer.
For more information on uploading from your computer, please see the following article.
How do I upload from my computer?