These children were studying in their room and when we asked the artist for two copies of the scene, he left one of them incomplete. Be an angel and click on the parts which are different and make both the drawings identical. Double up, because you are bound by a timer.
Move the cursor over the picture on the top and scan both the pictures simultaneously. When you spot differences, click there so that both become identical. Correct clicks give you points and wrong ones snatch your precious points. You may use hints, but then they cost 3 seconds in your timer.