IIFE module VS. ES6 module

counter-in-ES6-module.js

let count = 0;

function get() {
  return count;
}

function add() {
  count += 1;
}

export { get, add };

// another file that import above file

// import * as counter from './counter.js';

// counter.add();
// counter.get(); // 1

counter-in-IIFE.js

let counter = (function () {
  let count = 0;

  return {
    get: function() {
      return count;
    },
    add: function() {
      count += 1;
    }
  }
})();

counter.add();
counter.get();  // 1