How does Angela Carter use imagery in Nights at the Circus?

Imagery:

He would have called himself a ‘man of action’ He subjected his life to a series of cataclysmic shocks because he loved to hear his bones rattle. That’s how he knew he was alive.

What a cheap, convenient, expressionist device, this sawdust ring, this little O! Round like an eye, with a still vortex in the centre; but give it a little rub as if it were Aladdin’s wishing lamp and, instantly, the circus ring turns into that durably metaphoric, uroboric snake with its tail in its mouth, wheel that turns full circle, the wheel whose end is the beginning, the wheel of fortune, the potter’s wheel on which our clay is formed, the wheel of life on which we are all broken. O! of wonder; O! of grief.