My background is in old-school web development and LAMP stack development mixed with Linux server administration. Meaning I can code HTML, PHP, CSS and JavsScript—as well as man
The problem you have here is that you have placed the gravatar-image.js file in the templates/components folder and it should be in the components folder. Inside templates folder goes only *.hbs (templates is used for route templates and templates/components is used for component templates).
There is another way of structuring the folders called POD in which you have a folder with the name of the component and its files inside. With your component would be like this:
gravatar-image/component.js
gravatar-image/template.hbs
Check this tutorial if you are interested in using this POD structure.