Okay, so I store an associative array in my _config.yml that has:

baseImgURL: img
fileName: ['glyphicons-halflings-white', 'glyphicons-halflings-black',

Now for magic the Jekyll code in this gist, allows me to do this:

{% assign siteImgArrayObject = 'site.img' %}
{% include FG/twitterbs_image_helper %}

Tada, just two lines. Three lines is I need href urls. Is that not neat? Thus I can do strips of images without the messy coding. All due to storing some metadata in my_config.yml.