July 2015 - last edited October
Please note: this is has been adapted to the new Origin client.
Previously with Sims 3 games, each and every expansion pack and stuff pack had its own individual tile. It used to look like this:
After the update, you only have the base game showing:
To find your expansion and stuff packs now, right-click on the Sims 3 icon and choose Show Game Details. Choose "Extra Content" and you'll see them there.
As you can see in the above screenshot, some EPs have different statuses.
To download your games, select download. Origin will then startup the normal downloading process for your game.