Didn't get the ending

This movie ending is highly emotional and the ending is like the whole movie. It's funny as hell and kinda of sort of a 60's counter culture with drama infidelity overtone confusions with a free love kind of thing. Kind of hard to explain almost cosmically surreal. I think the ending when they are in the parking lot should of been longer with more faces starring at one another. The point was made but like the whole movie it just goes too damn fast.
I wish people weren't so hard on Dyan. She is a beautiful person and yeah her make up was a bit awkward but later on in films you see what becomes of her. She was like a Ellen Barkin of the time.

The people who followed them outside were all arranged in couples. There were young couples, old couples, couples of various races, even gay and lesbian couples. Meanwhile the song plays: "What the world needs now is love, sweet love." Then they all began to mingle briefly, before pairing off with their original partners again.

It represented how true happiness is found in a committed relationship with the right person, rather than in the "free love" and open marriages that people were experimenting with in that era.

I think it signified that there are millions of couples on this planet wanting to find their own kind of happiness and trust in a variety of ways. Also, the ending is very ambiguous as to what exactly happened and how they each felt about it.

It is also a callback to the beginning of the movie where the therapist at the retreat is having everyone in the group just look at each other because "no one really looks at each other." So, we have that once again at the movie's end.