Quote from Lord_VG:
Kirby Canvas Curse - Low% = No Medals (5.7%)
IIRC an any% run would collect no coins anyway - all coins except one require detours and the remaining one (first coin in first level) is avoided as well to avoid the delay caused by the help message that pops up when collecting it. So there would be no difference between any% and that low% definition.
Maybe a better low% definition would be "no medals and no powerups (unless absolutely required for completing the game)".