I don’t see anything referencing “scene” in the above code.
I’m going to assume that the only code you have is what was posted in your other forum thread. In your particular case, it looks like you copied a small snippet of a Composer scene, without the rest of the related listeners to actually get it to run correctly. Please note, blindly copying and pasting code that was found on the internet or even other Corona forums posts will rarely result in a solution.
I strongly suggest boiling down your project to the absolute bare bones. Get the images to show up. Ensure that you can attach listeners to them which print out data about the images. Check for the different phases of a touch listener on those images. Below is the Getting Started guide for Corona; it will walk you through a lot of these concepts.
https://coronalabs.com/resources/tutorials/getting-started-with-corona/