Pioneered by Edward Steichen, Lewis W. Hine and Tana Hoban, photographically illustrated “concept” books have never had a more potentially receptive audience. In recent decades, the ranks of photographers making occasional forays or full-time careers as picture book artists have swelled, while the uses to which they apply the medium have become more varied. For “How Are You Peeling? Foods With Moods,” a concept book about human emotions, Saxton Freymann photographed oranges, apples, tomatoes, onions and peppers, all carved like mini jack-o’-lanterns with uncannily lifelike expressions. Other photographers — Susan Kuklin, Ken Robbins, Shelley Rotner and George Ancona, to name a few — have embraced the picture book as an outlet for the kind of humanistic photo essay once routinely showcased in magazines like Look and Life. Still others employ digital tools such as Photoshop or, as William Wegman did for his deadpan mash-ups of classic tales featuring an all-Weimaraner cast, conjure photo-theater magic via the old-fashioned method of staging scenes for the camera — to produce images that, alluringly, manage to look real and unreal in equal measure.