A designer can say they are good at making complicated information understandable. A portfolio lets someone inspect a map, an exhibition panel, or a report they helped produce. The conversation can move from a general claim to choices visible in actual work.
Portfolio-based interviews use those examples to explore decisions and abilities in depth. The collection is selected evidence, not a complete record of everything the person has attempted.
Imagine a designer presenting a striking public-information poster. A useful discussion might reveal that they chose the layout but another colleague supplied the illustrations and text. Clarifying that division makes the example more informative; it does not diminish collaborative work.
A portfolio can also reveal the constraints behind a result. A modest-looking project completed with a tiny budget and difficult accessibility requirements may demonstrate more relevant judgment than a polished piece supported by a large team.
Selection creates its own distortion. People with permission to display prestigious projects have an advantage over those whose strongest work is confidential or invisible maintenance. A portfolio opens a window onto capability, but what can be shown and how it is interpreted still shape the view.