Extending Sprite Class

This is more of a JS question really. I know the solution, I just need to know why this won't work, opposed to that.

I am very new to PIXI and just barely grasping the concepts of oop so bare with me. What I'm wanting to build is an array based keyframe animation system ie (player.add.animations([3.5.9.10], walk, fps)). Of course I don't really like using game engines because I feel like I won't really be "learning" anything.

let Container = PIXI.Container, 
                autoDetectRenderer = PIXI.autoDetectRenderer,
                loader = PIXI.loader,
                resources = PIXI.loader.resources,
                Sprite = PIXI.Sprite;

        icon = function(img, type){ 
           var self = {
               img: img,
               type: type
               
           };
            
            return self;
        };

        icon.prototype = Object.create(Sprite); 
        icon.prototype.animate = function(){
            console.log("test");
            
        };

        var meow = icon("rwqerq" , "asdf"); 
        meow.animate();

So I was wondering why meow didn't inherit the .animate method, the console says its a function. I know that removing "var self = {}" and "return self;" will fix the problem, along with using "this.img = img;" and the "new" keyword will fix this problem, but again, I just want to know why this doesn't work opposed to the solution, so I can expand my general js knowledge.