It's not terribly intuitive why this works, I probably need to add something to the docs about it. The deal is that when you hard-code an ImageName on an Image meter, it will load it and "cache" it, to save on reloading the same image over and over and over on every meter update. Doing that on every Image meter would be a relatively large and pointless hit on the CPU. If on the other hand you set DynamicVariables=1 on the meter, then it will fully resolve all option values on every meter update, including loading the image.While you wouldn't want this on static images, when something is changing the image behind the scenes, leaving the file name the same, this is how you address it.