I see that the 'now playing' artwork is stored in:
/Library/Application Support/Perceptive Automation/images/Sonos/
Mine is called:
/Library/Application Support/Perceptive Automation/images/Sonos/Bathroom_art.jpg
In a control page, I tried making a new 'refreshing image url' with the url:
/Library/Application Support/Perceptive Automation/images/Sonos/Bathroom_art.jpg
and
http://192.168.1.148:8176/Library/Application Support/Perceptive Automation/images/Sonos/Bathroom_art.jpg
Neither work. Any tips?