“After a protracted identity crisis, the Brooklyn Museum has decided that local, not global, is the direction it should take. Rather than struggling in vain to put itself on the map for a Manhattan audience, it is joining the campaign to make a gentrified Brooklyn the place to be. The museum points to its new front entrance on Eastern Parkway as evidence of this grassroots connection. So, too, is “Open House,” which, in its casual way, posits Brooklyn-ness as a cultural ethnicity.”