What does being "judgmental" mean?

For the longest time, I didn't understand what being judgmental means.  Friends have proposed that it is making judgments that hurt the other person's feelings.  That could be the case but it's pretty to hard to know what statement would hurt someone''s feelings.  We often say things that unintentionally hurt people.  Fortunately, I came across nonviolent communication and Marshall Rosenberg's poem perfectly captures the meaning of "judgmental".

I can handle your telling me
What I did or didn’t do.
And I can handle your interpretations
But please don’t mix the two.

If you want to confuse any issue,
I can tell you how to do it:
Mix together what I do
With how you react to it.

Tell me you’re disappointed
With the unfinished chores you see,
But calling me “irresponsible”
Is no way to motivate me.

And tell me that you’re feeling hurt
When I say “no” to your advances,
But calling me a frigid man
Won’t increase your future chances.
​
Yes, I can handle your telling me
What I did or didn’t do,
And I can handle your interpretations,
But please don’t mix the two.