The designers arrived at a very clever solution (shown in the plan above). They set the entire pediment (D) at an angle relative to the gallery, so that the sculptures do not simply line one side of the long space. This also presented the viewer with a more frontal view when she entered from the short side of the gallery, rather than an end-on view down the long sculptural lineup. Building on this idea, the pediment was set on a trapezoidal base (E) of which one long side parallels the gallery wall — thereby incorporating it seamlessly into the space, rather than allowing it to look arbitrarily, bizarrely skewed. The base itself is cunningly engineered to serve several purposes: it unifies the objects into their original grouping; it emphasizes the objects by elevating them above floor level; and the three steps leading up to the pedimental sculptures invite the viewer to approach, climb up, get closer. The cherry on top is that its trapezoidal shape echoes that of the ancient triangular pediment, as if projected here onto the ground. This final subtle touch would likely not be noticed by a visitor in the room, but may well have produced an unconscious kinesthetic impression that would reinforce the concept of the show.
(The catalogue for the show is here, while several photos of the sculptures can be seen here.)