Jigsaw puzzle

This afternoon mummy saw Ethan successfully put about 5 out of 12 pieces of jigsaw puzzle by himself without mummy and grandma help. Mummy was so impressed because mummy thought that he might need a few weeks before mastering it. But seems that he picks up these thing quite fast.

At night Grandma told mummy that Ethan knows how to put all the puzzle in by himself. Mummy asked grandma whether is she sure or not? Is it that grandma helped? Grandma replied that she did not help, she only gave the tip that put the beside puzzle first before put the middle one. Unfortunately mummy didn't see Ethan put all the jigsaw puzzle by her own eye. Never mind, still have chance because Ethan likes to play these two puzzles recently. Hope that mummy can take the video of Ethan playing the puzzle and completing them himself without anyone's help or hint.