On Fiverr, a buyer can compare multiple sellers quickly. A new profile may have few reviews and little platform history, so the buyer looks for other signals of competence and reliability.
A portfolio can reduce uncertainty. Relevant examples show the kind of work you can produce and help the buyer decide whether your style and capability fit the task. Generic samples are less persuasive than work that resembles the service being offered.
Clarity also matters. A strong gig explains the problem you solve, the scope of the service, what the buyer receives, and what information you need to begin. Proof of work supports that promise.
Early freelancing is therefore partly a trust problem. Better evidence cannot guarantee orders, but it can give prospective clients more reason to consider you.