Each of the 5 tiles represent a group of letters/numbers. The reason you see 'EABCD' is because he is only using the first (blue) tile. If you wanted to type 'n' you would put your finger on the yellow, which contains 'KLONM', and slide it to the fourth tile.

The numbers I'm not sure. I think it is the same concept with 1-4 on the first tile (blue) and other numbers on other tiles.

Still doesn't seem like it would be faster for typing.

Blue (1st) tile is EABCD, Green (2nd) is FIGHJ, Yellow (3rd) is KLONM, Orange (4th) is PQRTS, and Red (5th) is VWXY.