The length of this dress is a bit risqué for the office which is why I paired it with flats. Whenever you think the length of your dress is too short for the office DON'T WEAR HEELS! Flats will help your legs look shorter. FYI I love this blazer and its also on sale at J. Crew.
Last FYI... I use breast tape in the summer to forgo having to wear a bra. Here's the link for the tape and nipple concealers I typically use (be careful using these I've read some bad reviews, but have never had issues removing them). Breast TapeNipple Concealer