Broken Cable Damages Arecibo Observatory
ucf.edu
ucf.edu
Perhaps it's an optical illusion. This photo seems more regular and confirms the tie-down aspect (I'm sure it's how the curvature is maintained).
https://forum.nasaspaceflight.com/index.php?action=dlattach;...
I don't think any are intentionally different heights. Part of it could be the thing was built nearly 60 years ago but also it doesn't need to be perfectly accurate to securely be tensioned.