I personally think this panel isn't that intuitive and is overly complex.
The icons make sense, that you can selectively chose which side to apply a decoration/rule to, but having all the indent options below don't.
I'd expect there to be only one input box there and for it to be called Offset (as I'm expecting the border/rule/decoration to applied to the selected side of the text frame that I'm working with and to apply to the whole length of that side.
Currently selecting the top icon applies the rule to the top as expected, but it doesn't get applied to the full width of the frame unless I stipulate "relative to" -> column for either left and right. This really is baffling - in my opinion.
In regards to the icons - these too could be simplified, as the the hatching adds a visual confusion and distracts from the highlighted edge element - which requires more visual weight