Peter Paul Rubens: 'A View of Het Steen in the Early Morning', 1636. Oil on Oak. Oil on oak.131 x 229.cm. National Gallery, London

Alberti defined seeing a painting as looking through a window but, you can look out of or into a window. Looking at pictorial space is a reciprocal process. Norman Bryson (‘Vision and Painting’, page 96) points out that the viewer’s space, on this side of the picture plane, has differed over time. The dramatic liturgical theatre of Byzantine Christendom; you approached the image in a full architectural setting with aural context. You moved from devotional icon to icon in a set pattern, at a particular time of the year, according to prescribed physical ritual accompanied by prescribed sounds and of course smells, incense etc. The contested piazza of the Renaissance self; always measuring, always calculating proportion, always negotiating a better deal with God. The pure white cube of the fiercely convinced, Protestant communicant. The contingent world of the modern being, a fluid range of virtual selves, constantly subject to a vast choice of undifferentiated stimuli.

Perhaps I was aware of this as I took my usual place in the National Gallery, on the bench before Het Steen on a Friday evening. Perhaps it was because, on leaving the Leonardo exhibition, I had seen Professor Martin Kemp (the international authority on da Vinci) in the Gents, prepping himself for his evening talk. He was dressed in a blinding white, collarless linen frock coat, buttoned to the neck. The neckline was giving him problems and took time to adjust – much fiddling and staring into the mirror. I last saw him, in the flesh, at a talk some 8-10 years ago. He seems curiously ageless, although his hair, then a dazzling black, now has shades of deeper red; we know he’s worth it. Outside, he is greeted by attendant young women in flowing dark tailoring, they whisk him away to bathe his brow in perfumed oils; aah the life of the eminent art historian.

Perhaps it was because the Leonardo show was so crowded (only a three hour queue to buy a day ticket, time quickly lost in explaining the processes of Christianity to a puzzled Malaysian Economics student struggling with terminology in the exhibition hand-out). An exhibition crowded with a certain class of person, fragrant is the term I think, modulated voices and modulated décolletage on show as well; parties to go to I suppose.

Perhaps this was why I was more than usually aware of others as I sat in front of Rubens’ joyful autumn.

A Study of Hand Gestures in Front Of Het Steen

Older hands are often clasped behind the back, male tending to one hand holding the clenched other. Female hands seem to be relatively open. Younger hands tend to hold digital devices in front or to the side, or carry bags, handbags or labelled shopping bags.

A couple walk past, constantly changing their hand grasp with each other, sometimes fully entwined fingers, sometimes laid palm in palm, sometimes holding little fingers as though they are about to pull a wishbone. They read the label, ignore the painting.

“It’s very nice, this landscape, quite a size, but just a bit big for our lounge”

Two women, middle aged, one in a pale pink cardigan, the other all in black. They are clearly absorbed by the painting and keep making paired movements, each pushes her hands together from a height about nose level and moves them down to about the waist, mostly whilst pointing to the carter and the house.

Three very small Japanese women/ girls (difficult to tell) make small dabbing movements as they point upwards to the painted sky; dab, then circular movement, dab, then circular movement. They stop, hold up their phones, standing like the three graces (two facing the work, one away from it) they each consult their mobiles, this uplights their faces with a delicate blue glow. Whatever they find, it returns them to the painted sky, more very careful anti clockwise gestures, this time with thumb and forefinger; precise and in a single plane.

The digital light from the three graces glowed briefly across the silver birches in the paintings foreground. The painted highlight on those top branches is frontally lit, as though a film crew had rigged up towers and put full spots –no coloured gels – onto the upper parts, prior to some swooping camera shots across the plain. But the sun, pale straw yellow, but yellow nonetheless, comes from the right hand horizon behind the trees. That the sun is low is clear from the sight and intensity of the shadows cast by trees in the midground; surely the trees should be in silhouette and dark at the top?

Young couple in matching anoraks stand with an arm around each other’s back. With her other hand, she takes out her chewing gum, examines it, rolls it between her fingers and pops it back in her mouth.

White haired, large middle aged man to equivalent companion, pointing with fleece clad arm whilst sat on the bench.

“Frank, what’s that building”

Frank gets up, looks at the label, waves his arm slowly in front of the painting in a horizontal manner

“It’s Birmingham”

A very large class of students appears, to draw the right hand Judgement of Paris, all hats and boots and tights. They carry A3 black sketchbooks, Seawhite’s finest held in front of them like protective shields, or perhaps devices to declare their allegiance. Time to go.