The pitch and tempos are shifted, but more nefariously, the pieces of the songs which don't fit the VI-I-V progression are removed and replaced by pieces of other songs which do fit. It's deliberate and meticulous cherry-picking. The only thing all the songs have in common is that they're in 4/4 and the verses and choruses all start on the VI chord. I should make a table showing the actual chord progressions from each song and how the creator deliberately masked out the parts of each song which are different from the baseline the creator chose.