Supporting artifacts are there to help give strength to your arguments in the Reflective Essay. For example lets say you did something cool or interesting in one of your classes that relates directly to one of the four core pillars in your essay. You can use the artifact as evidence to support your argument in the essay, by uploading it to your e-portfolio you have a place to site the work itself!
On the e-portfolio you can embed images, power points, project materials whatever works for you! Just give a brief description of the artifact itself for those browsing the page to understand why this artifact is important and how it is being used in your essay. For example below I have a digital timeline embedded in the page, I could talk about how this was a group project to build a digital timeline and go into a brief synopsis of how it relates to one of the core pillars. Try not to go into to much detail here because the bulk of your argument will be in your essay itself!