According to their website, it's a generic women's rights = general all human rights/ non-discrimination message against Trump, to stand up and get noticed.  Apparently people are "scared".

AKA they don't like Trump and he's racist/sexist/etc.

Again, other than the fact they don't like Trump there isn't much to their protest - no goal, specific or even general.  No policy.

Voting rights?  Wage gap?  Immigration, naturally - though they don't say it.  I suppose WOMEN FOR OPEN IMMIGRATION or WOMEN OPPOSED TO A DISCRIMATORY IMMIGRATION POLICY doesn't make good press.  And Pro-Choice marches have been done to death

Would be more to the point if they called it WOMEN WHO HATE TRUMP MARCH.  But that would make them sound like sore losers.