How to pass value in inline handlebars partial within ember

I have a .html file where following code is included:

<script type="text/x-handlebars" id="social"> 
    I'm partial content: <br>
</script>

Further down I use:

The above is rendering textual "I'm partial content:" ... but not the passed value ('x') from the key 'label'

I do not know why this is not workin? Using Handlebars 2.0 and Ember 1.9 (I know old versions but I'm editing existing tools from someone else).