Unity vs Uniformity.

#Black lives matter
N.O.W.
#I'llGoWithYou
PlannedParenthood
MANA
NARAL
Sex Workers Project
and other groups celebrate our differences while fighting together, in unity.

Uniformity is when a parent group silences the voices of those who are "too different", "too queer", "too uppity" or just too ugly or inconvenient or too far from the safe mainstream, knowing the movement will still be successful enough with white suburbanites to pay the exec salaries.

We're pretty much done with the latter, btw. We just can't afford to carry their weight any longer.

The way it's written in your post I would take it as unity = togetherness and uniformity = similarity. I think when people of different opinions/beliefs come together (unity) they are strong. When people of similar opinions/beliefs (uniformity) come together they are open to issues of homogeneity and polarisation.