A question I receive often is if it is necessary to have a "slide deck" for the portfolio presentation step of an interview.
My short answer is:
"If you want to maximize your chances of impressing the interviewer, then YES".
Of course, there are many factors that go into a successful portfolio presentation in an interview. Things like content, storytelling, pacing, clear communication, etc. will be crucial to your success in this exercise. However, you can think of a dedicated presentation deck as a useful tool that can help you better communicate your design skills and process.
If you think about it, a portfolio is optimized to deliver content and understanding through someone scrolling through your site.
You likely need paragraphs of text to provide context to the visuals you have. Otherwise how do they know what they are looking at and why it is important?
But in a presentation YOU are there to provide the context.
You don't want to just throw a paragraph of text at the interviewer... when you can just share a picture, use some visuals to highlight what you want them to pay attention to, and then personally step in to provide the context.
There is nothing worse than sitting through a presentation where someone is just scrolling quickly through paragraphs of text and you sit there.. trying to read it but then also being told to "just ignore that".
One thing that is hard to control in a portfolio project is the pacing that a user might move at when consuming the content. There are some tips that can help with this like clear distinctive headers, good spacing, subtle animations, tasteful visuals at the right places and good selective bolding/highlighting.
However because your portfolio is a "self serve" medium, you can't fully control people's focus and attention.
However, in a presentation, that is the name of the game. By selectively displaying nuggets of information at a time, you can effectively control the narrative and optimize the pacing for maximum impact. You can move quickly through parts when you see interest waning, and elaborate on parts where your audience leans in.