Easy to ignore the architecture, when presented with the fleshly pleasures of the expanded Tate Britain’s opening show, “Exposed - the Victorian Nude”. There’s a painting there which is a dead ringer for that famous Tatler cover of a naked Anthea Turner with strategically-placed python. Being Victorian, it is of course a religious subject - the Hon. John Collier’s “Lilith” of 1887. It’s in a section titled “Sensation”. You get the idea: Tate Britain has got to be seen to be sexy again, in order to compete with its own precocious younger sister, Tate Modern down at Bankside. The redevelopment is all part of this. But it’s not done with full-frontal architecture.

What you get at Tate Britain is not only a new side entrance, an agreeably lofty second entrance lobby and staircase, and a new double-decker set of galleries in the north-west quadrant of the complex, but also a rehang of the entire British collection throughout the whole building. Because galleries are repainted when they are rehung - and because the chosen palette of National Trust-approved Georgian-Victorian wall colours is used in new and old galleries alike - the deliberate effect is one of seamlessness. You hardly notice as you wander from new gallery to refurbished old gallery. The architects, John Miller and Partners, shape and proportion their new rooms - especially those for the permanent collection - to closely resemble the old ones. They have even used the same green-veined marble in the architraves to the doorways, chosen a similar oak floor and so on.