Drawing an Analytic zone in Chrome will show a second static image of the scene as the zone is drawn blocking what you are looking at and making it hard to see what you are sizing your zone to.
Pelco Cameras, Pelco Video Management
When drawing a zone for an analytic profile while in Chrome using the Spectra HDR or Optera IMM multisensor camera
This is an issue with how Chrome works with or analytic configuration
Be aware of the problem and best to use IE or a different browser when setting up analytic profiles