This is a packing challenge puzzle where there are 4 pieces (shaped like capital 'T' letter) and a wooden tray that has two sides (one side has larger compartment and the other one smaller compartment).
The object is to take the four T's out and try to fit them back in the tray.
The easier challenge would be to do so first on the larger tray.
Once you completed that task, try the harder task by fitting the four T pieces in the smaller side of the wooden tray.
Solutions for both challenges are available.