I think you could avoid breaking out `setSrc` into a separate function, and keep all the getting/setting code in `src()`, if you move this setting of the poster source into `init` and use `this.src()`, instead of it being in `createEl`. Does that makes sense?

```js
vjs.PosterImage = vjs.Button.extend({
  /** @constructor */
  init: function(player, options){
    vjs.Button.call(this, player, options);

    if (player.poster()) {
      this.src(player.poster());
    }
```

It might be nice to keep the getting/setting code close to each other since it's a little involved.