I have not said anything so far about this year’s Summer Exhibition, partly because I find it hard to navigate until the little red book of artists and prices appears, which makes it possible to find out who the work is by, and partly because I remember commenting on the rituals of previous years and don’t want just to repeat myself.   Suffice it to say that I always like the moment that it is unveiled, as will happen this evening at the Summer Exhibition Preview Party, with the galleries suffused with bright sunlight.   It feels particularly bright this year, with Joshua Reynolds wearing Yinka Shonibare’s sash and the big Gallery 3 painted the palest of pale blue:-