One lasted a day, the other a year and a half.
One was contained in a single location, the other was widespread.
One caused relatively minor amounts of damage, the other burnt entire cities down.
One didn't have any looting, the other had massive amounts of looting.
One was because people honestly believed that the people getting in power cheated during the election, the other was because a cop accidentally killed a drug addict.
One had no murders outside of the cops shooting at the protestors (no, I'm not counting the cops that offed themselves afterwards, they could've had all sorts of mental problems that were unrelated), the other was filled with violence and murder.
In short, BLM may have started out as a protest, but it quickly became a riot where the rioters actively caused chaos and murdered people for months on end.