Verify_images - doesn't react on non-jpg files

Hi guys,

I’ve moved to lesson #2 and got a strange problem with verify_images function
It works 100% without notifying any errors, but later, when I took a look at the data folder I found that there are not only JPG files, but other type of files too, non images ones, like PHP or IMG.

Is it a problem or not? Maybe I miss smth…