A gathered seat front is one of the small upholstery techniques that almost nobody notices and everybody feels. The problem it solves is where soft upholstery meets a hard carved rail: butt the two together plainly and you get a visible seam and, worse, a firm edge exactly where the backs of your knees rest. Drawing the fabric into close vertical folds along that edge softens it, both to look at and to sit against.
It costs fabric - a gathered front needs substantially more cloth than a flat one, because all that material is folded away - and it takes far longer to set, because the folds have to be even along a run that may be several metres long.
Our master Indian artisans gather from the centre of each run outwards, so any variation ends at the arms where it is hidden rather than in the middle where it would be obvious. It is the kind of decision that only matters if you sit on the sofa every day, which is exactly who this piece is built for.