Hi Samuel,
Guarav is correct that we have now included a formula field type of Rich Text. You would want to use the formula-Rich Text field type for this type of formula. Formula-Text was changed to no longer include options for html tags and just to render plain text. If you make the change in your field type to Formula-Rich Text you should then be able to call the images in your formula and get the correct results. Where did you see this tutorial at? It sounds like one of our older resources hasn't been updated to reflect the changes. Thank you very much for your time today Samuel.