query-row-content.js.es6

const QueryRowContentComponent = Ember.Component.extend({
  tagName: "tr",

  render() {
    
    //....
    
        if (user) {
          buffer.push(runTemplate("explorer/user", {user: user}))
        }
    
    //...
  }
});

user.hbs

// file: templates/explorer/user.hbs

<a href="/users/{{user.username}}/activity">{{avatar user imageSize="tiny"}} {{user.username}}</a>