Currently, Layouts can provide their own icon image which can be used in user interfaces. These icons could be in any size, color, dimensions, or style. As a result, user interfaces suffer as consistency is lost between different Layouts. The best example of this are the bright-pink icons provided by Radix, which look nothing like the default Panels or Display Suite Layouts (this isn't Radix's fault, we can't expect everyone to have the same design opinions).
The provided patch is a proof of concept for dynamically generated icons, which can not only help with consistency but could also be used in user interfaces to directly interact with regions. This also reduces developer strain as filling out config is far easier than creating an icon (which is a skill not everyone has).
Instead of making something fully featured, I wanted to put this forward and see if anyone sees value in what I've already done. Simply apply the provided patch, enable the layout_plugin_example module, and visit the path /admin/layout_plugin_example/layout_map/layout_example_stacked.
What you see on that page is the result of a new configuration value, "icon_map", which is a two-dimensional array mapping region names to their visual placement on a page. Widths of regions are determined dynamically based on the number of columns per row in the array. You can also hover over any region to see a tooltip containing the machine name of the region. See layout_plugin_example.layouts.yml for the exact structure used.
Thoughts?