This pattern can definitely go dressy or casual, depending on fabric choices. Someday soon I'll make it up in satin for fancy, but first I tried it out in two kinds of cotton gauze, in Bella's signature soft orange.
Textured on the bodice, plain in the skirt, it makes a comfortable frock.
I was actually quite short of fabric (a passalong in the stash) and cut the skirt far narrower than the pattern would have had it. It's still plenty full for every day though.