How to get/demonstrate asynchronous behavior in JavaScript promises

I read that

Promises also ensure order-independence. Separating the producer and consumer, so that they can execute independently, is the crux of asynchronous programming. With a promise, you can give a promise to a consumer before giving a resolver to a producer. They can then produce or consume on their own schedule and the promise synchronizes.

Trying to understand the Order Independence described above, I am writing up some code to hopefully demonstrate this. Basically, I wanted to create two asynchronous promises (based on downloading two images at two different times in partA() and partB()), and then resolve both using all.

var axios = require('axios');
function loadImage(imgsrc) {
    return axios.get(imgsrc);
}
function partA() {
    var promise1 = loadImage("http://cn.bing.com/s/a/hp_zh_cn.png");
    var promise2 = setTimeout(partB,20000);
    Promise.all([promise1, promise2]).then(function() {
    console.log("The images are loaded");
    });
};

function partB () {
    return loadImage("http://cn.bing.com/s/a/hpc20.png");
};

partA();

Here are my issues and questions are:

1. When executing partA() in the last line, I expected that I had to wait 20 seconds to see the success message because of the var promise2 = setTimeout(partB,20000); line (I had hoped that the two downloads happens 20 seconds apart from each other, for illustration purposes). Maybe I didn't use setTimeout right. But in any case, I got the success message almost immediately after I call partA() in the babel-node REPL. How do I properly get the delay?

2. In this example (if correct), how can I interpret the Order Independence in terms of produce or consume on their own schedule? Where are the sites of production and consumption?

(This is with babel-node 6.24.1 with --presets es2015 under Ubuntu 16.04)

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