index.js

//public/index.js
...

pc.onaddstream = function (obj) {
    var vid = document.createElement('video');
    vid.setAttribute('class', 'video-small');
    vid.setAttribute('autoplay', 'autoplay');
    vid.setAttribute('id', 'video-small');
    document.getElementById('users-container').appendChild(vid);
    vid.srcObject = obj.stream;
}

navigator.getUserMedia({video: true, audio: true}, function (stream) {
    var video = document.querySelector('video');
    video.srcObject = stream;
    pc.addStream(stream);
}, error);