Since your home is so very linear and full of 90 degree angles, serpentine beds of various plants always adds a nice texture.

I don't get the reasoning of why one style (rectilinear) would necessarily invite, or be compatible with, a contrasting style (curvilinear.)

I have to disagree with you OP. I don't see that the niche is asking for anything more than a single shrub, trained as a half-dome. The other, lower-to-ground windows, I think are going to be easily overwhelmed by the shrubs you have there. For those, I'd have a perennial in the 1 1/2' height range. Needs some small tree forms off of the house corners, too.

It looks like a cheery house ... except for the gloomy black posts and door. If you want a birdbath, gazing ball or some such thing, create groundcover beds under the trees and add it to one of those beds.

Yardvaark, it's a contrasting concept. Not that you can't do beds in lines with a linear house design, but some times curves can create more interest. Like an ornate frame on a modern painting.

Yes, Beverly, I understand the concept ... but think it is too often misapplied in landscaping, with an unlikelihood of it working out in a positive way. Using the word, "serpentine" implies multiple curves which, in my mind, is usually too much. A single, long, fluid curve, or possibly and S-curve, is usually about all that a rectilinear landscape can tolerate.

If the walk was being rethought here, it would be very good to pull it farther from the house in order that there would actually be room for standard foundation plants to grow. As it is, it's very pinched tight to the building. And a simple s-curve could nicely be worked in.

Yes, the walk hugging the house is limiting your flower beds where you need high impact. I would do a window box and a bird bath with a solar splash fountain in it for the birds.

I love birdbaths, so that’s what I’d do ... and with various perennials and/or smallish, wispy ornamental grasses in the area, too. It would break up the rows of shrubs nicely and give some interest there. Plus, happy birds. :)

really that is a perfect spot for some nice flowering shrubs I am not sure why you don’t want plantings there

While you're at it, plant something out in that sun-baked expanse of grass. A few ornamental trees would make the house look less barren.