This is Burda pattern 7678. It's a great basic piece to have in your wardrobe because you can wear it over skinny jeans or leggings. You could also dress it up with some sexy heels for an evening out or put some flip flops on for the day.
This was the first version of 7678 I made in a yellow and black striped jersey. The top ended up being so long it could also be worn as a dress shown below.
This is the second version I made. I shortened the pattern by about five inches so it wasn't so bunched up at the hips.
I read about this fluttery detail in Sew Stylish magazine. You cut out hearts and then gather them in the middle. You then tack them on the garment and they resemble butterflies. This fabric was a light pre wrinkled beige cotton jersey with a slight gold metallic sheen which is not evident but gives the top a casual evening feel.