Delay Setting Has No Effect

I have issues that might benefit from a Delay setting, such as some images failing to load, but no matter how high I set the Delay, Backstop takes the same amount of time to finish. With 70 URLs in backstop.json and a Delay of 10000 for all urls, 'backstop test' (or 'reference') completes in the same amount of time as when Delay is zero. Am I wrong in expecting the run time to be 700 seconds with these settings and to see the effect of the delay in the console output? (I realize 10 seconds is too high, but I'm just trying to convince myself if the delay is actually happening.) Does delay have a default upper limit? Is there any way to confirm it's working?

These are parameters I'm using:

"label": "HomePage",
"url": "https://test-www.anyurl.edu",
"referenceUrl": "https://www.anyurl.edu",
"cookiePath": "backstop_data/engine_scripts/cookies.json",
"selectors": ["document"],
"hideSelectors": ["div#cookie-handler"],
"delay": 10000