I think capris could totally work too, as long as they were more fitted. Espadrilles or flat grecian-like sandals would work really well with that look. Although if you were going for an uber-casual look, bermudas, a tunic and flips would work.
But overall, I think fitted capris would be the way to go, and not really loose ones, since most tunics are loose. Too much looseness in the pants AND the shirt could look really sloppy.
I've noticed some pictures pairing them with Bermudas too and that's also a cute look!
Here's 2 pictures of what I'm liking, with shorts or capris/cropped pants (not necessarily these specific pieces, but the overall look):