Complex sentence: Each arch of the colonade features a carved face on the keystone, and spandrel figures, whose comical references to real-life personalities (including Barnet himself) caused a controversy at the time of construction.
Split into simpler sentences: Each arch of the colonade features a carved face on the keystone, and spandrel figures. The comical references to real-life personalities (including Barnet himself) caused a controversy at the time of construction.