New Twiddle

application.controller.js

import Ember from 'ember';

const {
  get,
  set
} = Ember;

export default Ember.Controller.extend({
  singleVal: '',
  actions:{
    addField() {
      get(this, 'model.images').addObject(get(this, 'singleVal'));
      set(this, 'singleVal', '');
    }
  }
});

application.route.js

import Ember from 'ember';

export default Ember.Route.extend({
  model:function(){
    return {
      images: [ ]
    }
  }
});

application.template.hbs

{{#each model.images as |info|}}
  <label>image:</label>
  {{input value=info}}<br/>
{{/each}}

image {{input value=singleVal}}

<br/><br/>

<button {{action "addField"}}>
  ADD INPUT FIELD
</button>

twiddle.json

{
  "version": "0.5.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}