This does seem an extraordinary length to go to for what is temporary in nature. I wonder if these were designed for this place or are from a set of historic collections from ‘Hoardings R Us’ (no reference to the Australian shopping centre hoardings firm, Hoardings R US, is implied here, of course - it does exist). What ever it is it is all rather muddled and doesn't require an architectural critic to see that it is all so confused.
It seems to be yet another example of how public perception is so far removed from reality. What difference to the experience of the place has this made, to the way it functions or simply added to the cost to the contractor, funders and the public? It is obviously not a hoarding that will show what the permanent building will look-like after. It isn’t public art either. It isn’t even uplift. It is a phoney mask but we love our classicism. It seems purely to allay the fears that if we see construction huts and burly men with a crack showing we will be so appalled that we will write to our local MP. Perhaps a student competition to design the ultimate site hut is needed. Luckily the structures are temporary and before long they will disappear, presumably to another site in Westminster.