In case it isn't clear (it wasn't to me), you have to place at least one domino piece on every bear picture to finish the puzzles.
There's a trick to this if you're having issues with dominoes, especially if you're playing on Normal. Play the hidden object puzzle until you only have 1 or 2 pieces left. (Normal makes this easy: spam
as you go around the screen. Expert gives you a penalty after too many mistakes in a row.) Then press
on the D-pad. You'll have only 1 or 2 pieces left to cover. Then make a quick chain to that bear piece.
You can watch the achievement tracker to see this progress. It's a bit cheesy, but if the dominoes are getting to you, you can skip through a lot of the grind.