You can preview your render interactively via RenderMan's Image Tool or Render View.

Using Image Tool

Set Display Device to "it" (the default)

TODO: new image of ROP nodeImage Added

Using Render View

...

Go to Render View.  Select your output, e.g. /out/ris_ip1ris1.  And press Render .   

Crop Window

TODO: Does this work?

from inside the window.  

Image Added