Re Claire Danes, despite the posted picture, that woman is REALLY, REALLY flat-chested. I actually have a very similar body shape, and notice all the celebrities that have that body shape.
If you look at pics of Claire Danes from her teen years (the pic posted looks like her teen years), she is a little bit fleshier and at least has an ounce or two of breast tissue. In years when she was leaner, she doesn't even have that.
I've kept an eye on the super-flat-chested celebrities and there are a few who plainly flaunt their AA chests (Kate Moss, Kiera Knightley), and others who neither flaunt nor hide their small chests (Claire Danes, Kate Hudson), and yet others who stuff their chest with implants (Gwyneth Paltrow, for example).
Don't get me started. I'll go on a whole rant on this one topic!
On a total unrelated side note, women with super-flat chests are stupidly perceived as having "lost" their chest due to losing too much weight. To your co-worker: Duh, but no. Like, do you suppose I was a C-cup before I discovered broccoli? Nope. People like Claire Danes are have a mere few ounces of breast tissue, even if they are carrying extra weight, and then have even less than that, when they are lean. People who misunderstand this are kinda silly!
![stick out tongue :P](./images/smilies/tongue.gif)