Hello Bob,
Thank you for reaching out and I am happy to help!
I’ve checked your website for both cached and cache-bypassed status.
In both cases, I need to press Ctrl+F5 for the image to refresh and show the updated time/image.
This being said this depends on how this image is being added and how it’s refreshed.
To confirm this, does the problem persist if the W3 Total Cache is disabled?
Thanks!