You seem to lean towards a lot of neutral ivories in your ideabook. The cabinet color already does come off soft, the number of cabinets however creates the harsh angles. You need either vanity round bulbs and a large mirror that spans that wall or you can add gold drawer pulls, warmer lighting and keep the surface clutter free. Adding gold, lots of light and keep the colors to ivories/neutrals will lighten the harsh look.

I don't see the round sconces you found adding that softness. Not because of the style but because of the color. They come off plain and cold because they are in a colder shade. If you can find similar sconces in gold or use LED strip lights under the cabinet and above, the effect will be better.

Led strips are all over the internet now. You can find lots of beautiful sconces too, but the wall where the mirror will be, should be kept to a minimum. One row of lights above a large mirror that spans the entire wall should be a safe bet. Again you can add softness by adding lighting, flowers, gold or light brass pulls and keeping clutter to a minimum.

Thank you very much for your detailed reply. We already bought all hardware in brushed nickel (my partner does not like gold), but will most certainly look into lighting, mirror and other accessories to soften the look.

You could definitely add some softness by adding mirrors with rounded corners. Here are some ideas. The last photo is just there to show how they installed the sconces on the cabinets, so it gives better light for the mirror. Try taping up different shapes on the wall to see what you like best.

Your OP didn't mention anything about hardware already being bought or installed already so the assumption was you were to open to those options.

Regardless if everything will be silver/non-gold because of your H, then I think focusing on a large simple mirror and lighting that is bulbous in shape would be best to soften the area. I would not suggest individual round mirrors because it would add more "sections" to the already bulky cabinets.

The colors are nice, flooring is nice, and adding too many shapes would obstruct that "softness" you're asking for.

Softness can come from the sconce shape, light bulb color and minimal mirror.

This is a more clear idea or picture of how one single mirror and sconces above it would look more neat, linear and soft than 2 or more mirrors on each side.

Both can look nice but the unity and harmony from one large mirror is more visible to the naked eye.

I wouldn't use those sconces in this photo however. Something more linear (like yours sideways even) would be cleaner.