Another case of putting daffs right in the middle of the lawn -- to allow for mowing later, after the flowers have bloomed, some people pin down the leaves with string so as not to cut them off prematurely.
Fig 1. shows some blue flowers which have also been scattered in this lawn, which is between Belvedere Castle and the Shakespeare Garden.
Behind the lawn is a fence and some sticker bushes which help to obscure the sunken 79th Street Traverse, and Figs. 2 and 3 show daffs planted amongst these. Daffs can be planted underneath deciduous shrubs or trees because they will bloom and die back before the leaves come in and cut off the sun.