Floppy Cube turning - i.e. an edge piece may only twist if there is at least one corner piece adjacent to it. The mass-produced version does not feature this mechanism, which allows edge pieces to twist "on their own" - causing the puzzle to be considerably easier. The four edge pieces now have 4 orientations each on the Super Floppy Cube (compared to the Floppy Cube's 2); therefore, the edges can now be orientated in 4 different ways. However, the edges still cannot be permutated. There are now 12 different locations that the four corner pieces could be located in (up from
Impossible cube ambiguity present in a Necker cube illustration, in which a cube is drawn with its edges as line segments, and can be interpreted as being in either of two different three-dimensional orientations. An impossible cube is usually rendered as a Necker cube in which the line segments representing the edges have been replaced by what are apparently solid beams. In Escher's print, the top four joints of the cube, and the upper of the two crossings between its beams, match one of the two interpretations of the Necker cube, while the bottom four joints and the bottom crossing match the