You can also add a sew-in strapless bra front to a purchased dress if you just want a bit of modesty/coverage. Fabric stores sell them for less than $12. You could use small safety spins to fix it in place instead of sewing it in permanently.
Side Note: I was in Joann's Fabrics today and they are having a half-off sale on all notions. In addition to sewing notions, like pins, needles, bobbins, thimbles, etc., it also included an entire wall rack of "dressing notions." There were replacement clear bra straps, clear strap cushions, invisible body tape, bra cups/bra panels, and lots of other clever things. I must have stood there for 10 minutes checking everything out. I never noticed that panel before, but I couldn't think of anything I really needed but I wanted to mention it to our members.
Back on topic: Love the twisted back straps of that dress! It's a great look for that model's very-broad shoulders and tiny hips. Really emphasizes the "V" bodyline in a flattering way.
My oldest DD used to have a similar bra for a Show Choir dress. She said the plastic strap in the back made her sweat and itch, but it was invisible. They were in costume for hours, performing multiple times during each show, which is different from skating a short Basic Skills program. Just a little info.