Architecture Applicant - Book form Portfolio

<p>"First time Freshman Architecture Applicants: Portfolios may now be uploaded at slideroom for architecture majors as well as art and design at <a href="https://pratt.slideroom.com%5B/url%5D"&gt;https://pratt.slideroom.com&lt;/a> for your convenience. You may also submit images in book form."</p>

<p>Can someone clarify the 'book form' we can upload onto Pratt's slideroom? (I think the 'book form' is different from sending(mail) print images to Pratt.)</p>