Is the cache timeout somehow not working?

Is my understanding correctly, that you can change the “expires headers” of resources on specific pages with the “Cache Timeout” tool?

I wanted to set a very short expires header for resources on a specific page. Its URL looks like this: https://mywebsite.com/subpage
and I applied the rule like this:

Start With: subpage - Once Every 1 Minute
https://mywebsite.com/subpage(.*)

However, when I check the expires headers with Chrome Developer Tools, they are still set to 30 days instead of one minute. And also the cache clearing doesn’t work.

I want an image to be loaded again from the server instead of the browser cache, because its content changed, while the file name stayed the same. It doesn’t work with the timeout tool.