I expect there to be separation between the segments because of the padX, but there is not.

{-# LANGUAGE FlexibleContexts #-}
{-# LANGUAGE TypeFamilies #-}
module Main where
import Diagrams.Prelude
import Diagrams.Backend.Cairo.CmdLine
ex :: Diagram Cairo
ex = foldl1 (|||) $ map (padX 2) [l, r # lc red]
where
l = strokeP $ p2 (0, 0) ~~ p2 (1, 1)
r = strokeP $ p2 (1, 1) ~~ p2 (2, 0)
dia :: Diagram Cairo
dia = (centerXY ex # pad 1.1)
main = mainWith (dia # bg white)