This reminds me of a show I saw on paintings done based on dreams, during a rise in fascism. You saw something, the artist saw something and put it into visual, tangible form.
Have the impression that most artistic/poetic/prophetic expression comes as an inward vision which is then often attempted to be accurately expressed again outwardly.
I wonder if God was revealing to you a functional form that would work in ways you didn't expect. Unveiling an invention.
From time to time, an idea pops into my head, and leads to something wise and beautiful, and the sense I have is that it's a gift, from One Who Is a lot Better and Wiser than am i.
A curve suggests flexibility, but sometimes provides unexpected strength. Look at the arch used in architecture -- it is able to hold itself up and cover without a ceiling or additional supports. We don't usually see it sideways, but imagine what would happen if a weight came down from the top -- it would bend without breaking.
For practicality, the outward curve allows more room for the plants to grow. If stems are tied to the poles, the fruit can hang down more freely. You might even find leaves going toward the sun in a more suitable way.
Secure in the concrete, you don't need to worry about it balancing properly.
Now all you need is notches to tie up the weight of the plants.
In this instance the curves do add strength, because that lends the uprights to lean into each other, but with perhaps a more graceful look, than if "straight-lined".
The curve allows more room on one side, but less on the other, which fits with putting the two larger (tomato plants) in the "enlarged spaces".
Plan on drilling 7 holes though the crosspiece, (5 between and 2 outside the curved uprights) and hang planters from "S" hooks.
The balance was necessary/helpful while erecting, and before concrete was mixed, poured, and set. Concrete deemed fitting because of the potential for high winds, and the combined weight of 7 planters estimated to be over 200 lbs.,(especially when wet).
More to be valued than gold or silver - arable soil. Invest in good dirt - compost, and grow as much of your own [organic] food as you can.
It lends a greater sense of thankfulness, is healthier, and more economical + secure.
May The Lord's Blessing Be Sought & Found to The Glory of God !
wm