Sometimes it is not the work on the walls of a gallery that excites, but what lies piled against them on the floor, or stacked up in the storeroom.

It pays to look around and I found the truth of that, yet again, on a visit to the One-Off to the west of Nairobi, at Rosslyn.

There, I came across paintings in the packed office above the main gallery by someone new to me; an American called Olivia Pendergast.

They were polished and immaculate. But left me puzzled.

Pendergast’s subject is primarily the human figure and she has produced a suite of portraits from Kawangware, that sprawling enclave just west of the Kenyan capital.

This is an artist who gets the basics right. Her oils, for instance, are brushed onto paper first rigorously covered in a ground of gesso front and back. The paint is clear, fresh and applied carefully, her faces built in a considered mosaic.

Pendergast likes to show the construction of her figures, in the same way that modernist architects relished exposing the brightly coloured steel support beams and ducts of their buildings. In this she is also like the British figurative painter Euan Uglow who left visible the ticks and crosses of his measurings, creating in the process a sort of sculptural monumentality.

Thus Pendergast leaves on view what underdrawing remains uncovered by the thin washes of her oils, and where it becomes obscured, increases the structural integrity of her figures by outlining the limbs, for instance, with a confident pencil line.

Mostly single figures set on flat planes (sometimes sharply cropped like the photographs from which they derive) tend to leave large areas of background, and these she enhances with a variety of shapes abstracted from the sitters’ surroundings — suggestions here of a window, a door, the angle of a table, the striking cliché of a red umbrella, sometimes an animal; chicken, goat dog or bull — and fills in the blanks, as it were, with sgraffito made, at a guess, with the other end of her brush.

What a intriguing painter. Clearly a fluent and practised performer, there are a number of surprises in her work.

One is that her faces all look vaguely similar, another is that she tends to ring the changes on a restricted repertoire of poses… the standing man or woman, the seated figure, on chair or floor, arms on lap or by their sides, legs akimbo.

All share small heads, large flat bodies and long spindly limbs with big hands and feet, giving a certain expressionist energy to the otherwise still poses. Pale colours predominate.

Another odd thing is that at first sight, whether small (A4 like the ones pictured above) or large (around 5ft by 3ft, like one propped up at the One-Off) they seem to have equal power. Increased size bestows neither strength nor authority; nor does reduction create either intimacy or intensity.

The smaller works that I saw were more anatomically accurate however (the heads were proportionately larger) and perhaps for this reason, the distillation of her mannerisms might ultimately produce works that would give more lasting satisfaction.

All Pendergast’s subjects seem passive, uncomplaining, happy enough to sit for a stranger. All the pictures are easy on the eye and would look pleasant on the wall… souvenirs of good times and warm people who became a little bit lost in life.

I viewed portfolios of Pendergast’s work on her website and what struck me was that her figure paintings from Malawi and Ethiopia were little different from her more recent work in Kawangware; the features, clothes, pared down surroundings and even the colours were all remarkably similar.

What do we conclude then? That these are cyphers, consistently rendered symbols of an African experience as much as real look-alike portraits?

Elsewhere on the website (I should become an IT reviewer) are a group of Pendergast’s landscapes. They shimmer and glint as though touched by the sun. Yet in these the leafy canopies are the same large flat planes as the figures’ bodies and the tree trunks become the same spindly limbs.

Unmistakably by the same hand as the portraits, they too speak of thorough training, professional execution, a laudable sensitivity to line, volume and colour — everything you would expect from a consummate artist, in fact. Except soul.

Frank Whalley runs Lenga Juu, a fine arts and media consultancy based in Nairobi.