It's back to work, Boss Lady. Of course, we're also counting down to the Holidays, which means work and life are hectic and you certainly have the freedom to be a little more comfortably casual in the office (at least, that's what I'm doing until I get an email from HR).
The Tunic Shirtdress by Mossimo from Target is probably a little bit too short at mid-thigh to wear by itself, but over a pair of thick leggings, it's perfect. If your office is casual enough, you could even do it over a nice pair of "work jeans." The dress is made of 100% cotton poplin, has a loose fit, and and the 3/4-length sleeves are perfect to give you the agility at your laptop. (I hate sleeves that get in my way when I'm working.)
The dress is only $15.99 at Target and also comes in Caffe Latte, Blue, and Black.