Picture of 4x4, 4x3 and 4x2 sized properly and require an additional block to the right. Was founded in singleplayer when i tried create picture 4x3 on wall 4x3. Then i placed additional blocks to the right and to the left (that is 6x3) i understood that picture require an additional block to the right (i broken 3 blocks at the left and it dropn't, but when i broken 1 block at right it was dropped).