This allows players to separate the placing and building aspects of the game, which makes the game a lot easier than the next step in the difficulty, which requires the piece to be built before it touches down:
If you do not have the piece entirely built before it touches down, it will explode and cause the crowd to turn against you(this will also happen if you are off beat or try to build outside the predetermined area):
The next step up in difficulty, though, is our favorite. If you do not complete the piece before it touches down, you are off beat, or you try to build outside the predetermined area, the piece will turn white and will not count toward clearing lines, as seen on the bottom 2 lines here:
In order to clear lines containing white blocks, you must clear a touching line above it, which can include a line containing white blocks(creating a chain reaction). As you can see in the image above, I was about to clear the line above the lines containing white blocks, here is the result:
