The National Photographic Portrait Prize exhibition is selected from a national field of entries, reflecting the distinctive vision of Australia's amateur and professional photographers and the unique nature of their subjects.

What constitutes a portrait is a question that has been discussed often, with diverse views being expressed. For me, these words come reasonably close: "A portrait is an artwork that has been created about a person or persons which tells us something about them." That doesn't mean a portrait has to look like or clearly show the person's face. For me, revealing information about the person is the key element.

Forty-eight entries were shortlisted for 2020. There are two works that are collaborations between two artists. Two artists each achieved two shortlisted works. And five of the works are by Canberrans.

Oxygen Thief, by Lori Ciccini, stands out for two reasons. It is framed differently to the other works (artistically) and is not about a named person but portrays "the contemporary human". Arguably, it tells us more about the photographer herself. Nevertheless, it is an extraordinary, created image that made this viewer think.

Mike Bowers is photographer-at-large for Guardian Australia and also host of Talking Pictures on ABC TV. His image, Prime Minister, taken during a parliamentary vote, shows the PM sitting alone and looking uncertain, while other MPs stand in the background.

Brothers, by Steven Lloyd, was captured when two brothers reunited at a family gathering. Lloyd has succeeded in showing the joyous emotions of the occasion, as well as revealing the physical likenesses shared by Nik and Rouli.

Brenda L. Croft presents us with Matilda (Ngambri-Ngunnawal), a strong portrait of Canberran and Ngambri/ Ngunnawal Elder Aunty Matilda House. It is best viewed from a distance. Incidentally, fully one third of the shortlisted works are portraits of people with Indigenous heritage, not all having high public profiles.

Jarrah, by Charles Tambiah, was a standout for me. It is about a mate and reveals numerous things about him; his chosen clothing, vehicle and dog immediately establish an Aussie context for us. The inclusion of a footy adds to our knowledge.

Among the works by non-Canberrans, I particularly enjoyed Willie "Bomba" King, by Jason McNamara. As with Tambiah's work, this quickly reveals much about the person portrayed, whilst also inviting us to learn more. Dr Christian Thompson's Writing on the Wall is an elaborate and stunning self-portrait referencing the collective anxiety posed by climate change. Its vivid colours immediately attract attention.

1967, by Dave Laslett, invites us to consider what, if anything, has changed since the historic 1967 referendum when we voted overwhelmingly to include Aboriginals in the Census.

One of the prize's 2020 judges, Nici Cumpston, with Aboriginal heritage herself, has said it was refreshing to see so many images of and by Aboriginal people among this year's finalists. "Importantly, the NPPP is a democratic view of our society at this particular time in history, and the final exhibition tours nationally, which is a great gift for the nation." Perhaps that is a partial answer to Laslett's question.

There are other images of great interest for a variety of reasons, such as their storytelling, dramatic effects, background choices, and great subjects. It is most interesting to compare Hugh Stewart's Eileen Kramer is a dancer (which was highly commended) with the painting Elizabeth - winner of the Darling Portrait Prize - on display in the adjoining gallery space.

Another fine work, The Mahi-Mahi by Rob Palmer, was announced as the prize winner, despite a certain virus derailing the planned gala announcement event.