Rate of return when reinvestment rate changes

Dear guys,
I read these conclusions from and a bit confused. Please help me to be clear. Thank you.

  1. If the market YTM for the bond, our assumed reinvestment rates, increases after the bond is purchased but before the first coupon date, a bind investor eill earn a rate of return that is lower than the YTM at bond purchase if thr bond is held for a short period
  2. If the mkt YTM for the bond, our our assumed reinvestment rates, decreases after the bond is purchased but before the first coupon date, a bind investor eill earn a rate of return that is lower than the YTM at bond purchase if thr bond is held for a long period.