"Beautiful simplicity" means something that is both uncomplicated and pleasing to the eye or mind. It refers to the elegance and charm found in simplicity. Full definition
Our goal was beautiful simplicity which I think we accomplished with the straight line pieces we chose and the overall neutral feeling of the room. (einteriorsdesign.com)
It does all this with beautiful simplicity too. (roadtovr.com)
It's a wonderful reminder of how beautiful simplicity can be and the love that infuses our families. (sugarpiefarmhouse.com)