It is certainly a look. Not one that I particularly like, but each to their own. The danger of ultra casual is that it can cross the border into scruffy or slovenly. Not that it is happening here, but to my eye - you're very close.

I would suggest tucking in upper garments and go for high-waisted jackets (the old-fashioned bum freezer), would still give casual without being sloppy.

Regards

Chas