The first time is time limited for 7 days to win a pop-up bookshelf; if you don't get it in the time limit you will earn a kitchen playset. The second time you will get six outfits (no time limit) and the third time you'll earn 3 Lifestyle Points. As like other hobbies, you need to have one Sim reach level six; after that you can have three toddlers do the hobby.
There are six levels:
Grid Paintings and XP
|Hands||Grass Sunset||Dragon in the Garden||750XP|
|Rainbow Hills||Barney the Unicorn||Seaside||1,000XP|
|Oscar Octopus||Yellow Fish the Fish||Dragon with Heartburn||1,500XP|
|George Giraffe||Kitty the Caterpillar||Fish Fingers||2,000XP|