Are physical descriptions needed?
I just finished reading All Seated on the Ground by Connie Willis. (Delightful book, as I've found all of hers to be.) And when I closed the back cover, it struck me that there hadn't been a single description of physical appearance in the whole novella.
How could that be? I started paging back through it again. Okay, we have a single mention that the aliens could be mistaken for plants "[I]f it hadn't been for the expression on their faces". That's almost a description, except that plants don't have faces.
Further on, the choir director is tall and skinny.
That's it. No descriptions of figures, features, attractiveness, skin color, hair color, eye color, build...
And it worked. Not once while I was reading it did I wonder what anybody looked like. I thoroughly enjoyed the story, being able to picture it however I wanted to, without being jarred by the author limiting me to specific characteristics. Refreshing. And yet I didn't even notice until I was done. Skillful.
It reminded me of reading Dolores Clairborne many years ago. I was totally caught up in the story while I was reading. When I was done, it hit me that the entire book was written in first person dialogue. "No way", I muttered, and began leafing back through it to find where it switched. But it never did. The whole book was one person speaking. Damn, that's talent.