Masonry Attempt via CSS & Sort Order

components.image-gallery.js

import Ember from 'ember';
const { computed } = Ember;


export default Ember.Component.extend({
  tagName: 'ul',
  classNames: ['image-gallery'],
  classNameBindings: ['modifier'],
  modifier: null,
  
  sortedImages: computed('images', 'modifier', function() {
   if ( this.get('modifier') !== 'masonry') {
     return this.get('images')
   } else {
     return this._sortImages(this.get('images'));
   }
  }),
                         
	_sortImages(images) {
		const column1 = images.filter(function(value, index) {
      return index % 3 === 0;
    });
    
    const column2 = images.filter(function(value, index) {
    	return index % 3 === 1; 
    });
    
    const column3 = images.filter(function(value, index) {
    	return index % 3 === 2; 
    });
    
    const sortedImages = column1.concat(column2).concat(column3);
                                      
		return sortedImages;
   },
  
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  images: [
  	'https://placem.at/people?w=150&h=150&txt=1',
    'https://placem.at/people?w=150&h=250&txt=2',
    'https://placem.at/people?w=150&h=100&txt=3',
    'https://placem.at/people?w=150&h=110&txt=4',
    'https://placem.at/people?w=150&h=180&txt=5',
    'https://placem.at/people?w=150&h=150&txt=6',
    'https://placem.at/people?w=150&h=120&txt=7',
	]
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.image-gallery {
	list-style-type: none;
}

.image-gallery.column,
.image-gallery.masonry {
  column-count: 3;
  column-gap: 5px;
}

.image-gallery.grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-column-gap: 5px;
}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}

<h2>Mansonry Via Sort</h2>
{{image-gallery images=images modifier="masonry"}}

<h2>Column-Count layout</h2>
{{image-gallery images=images modifier="column"}}

<h2>Grid Layout</h2>
{{image-gallery images=images modifier="grid"}}

templates.components.image-gallery.hbs

{{#each sortedImages as |image|}}
	<li>
  	<img src={{image}} />
	</li>
{{/each}}

twiddle.json

{
  "version": "0.13.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
    "ember-data": "2.16.3"
  }
}