From the moment I put it on, I fell in love with it. Alo wins again! It looks simple, but the material feels great and I love the fit. The back is completely mesh, but it's only semi-sheer. Overall it's a pretty understated look. I got it in size S.
I was only wearing a bra under this top, but you can barely see it from the mesh back. So I don't think you need to wear anything under.
The front has little areas of mesh right under the collar too:
The hem and forearms are stretchy ribbed material in heather gray:
So from the side you can see the material difference between the front and the mesh back:
And here's the back up close:
Love this! It will be another top that I can easily wear to and from the gym, or casually on weekends. I think Alo makes some of my favorite to and from pieces. I wear the Rift LS so much, literally everywhere. Now that it's so hot out, I'm happy to have an alternative!