'Shamrock'
The guy up the ladder is trying to complete the twenty piece jigsaw of an Irish Shamrock
which is the symbol of Ireland
With your eye you should be able to complete it for him using the piece he is about to place and the other three pieces on the ground

If you have failed, here is the answer:-
The piece he is carrying goes in the bottom right hand corner
The piece closest to him on the ground goes in the second row from the top- second in from the right
The middle piece on the ground goes second in from the right, bottom row - The last piece on the ground goes top right hand corner!