You are not following up the training I assume,
var images=[
"mercedes.jpg",
"volkswagen.webp",
"toyota.jpg",
"subaru.jpg",
"audi.jpg"
];
Does not mean that they are available on the machine. To make sure, that they load, you need to put them in the directory "images", which is a subdirectory of the directory where your HTML file is.
/
|- index.html
|- images/
|- mercedes.jpg
|- volkswagen.webp
// so on
This is the way it should happen, otherwise the relevancy would break and you will not be able to show the images.
One more thing, when this happens ever, just right-click and open the resource in a new page. That shows the URL which is being built on the runtime. That URL can give you an idea of where the browser is looking for the resource. That way you can modify and target it to the location where your resources actually are.