It was the youthful freshness with which, even in advanced age, he followed his rapid impulses to art-creation.

No one was a greater child than he in the quickness with which he received a sudden call to poetry from passing events or scenes, and in the eagerness with which he seized them as subjects.

He took the big subjects now and then which the world expects to be taken, and treated them with elaborate thought and steadfast feeling, but he was more often like the girl in his half-dramatic poem, whom the transient occurrences and sights of the day touched into song.
He picked up his subjects as a man culls flowers in a mountain walk, moved by an ever-recurring joy and fancy in them--a book on a stall, a bust in an Italian garden, a face seen at the opera, the market chatter of a Tuscan town, a story told by the roadside in Brittany, a picture in some Accademia--so that, though the ground-thought might incur the danger of dulness through repetition, the joy of the artist so filled the illustration, and his freshness of invention was so delighted with itself, that even to the reader the theory seemed like a new star.
In this way he kept the use of having an unwavering basis of thought which gave unity to his sixty years of work, and yet avoided the peril of monotony.

An immense diversity animated his unity, filled it with gaiety and brightness, and secured impulsiveness of fancy.

This also differentiates him from Tennyson, who often wanted freshness; who very rarely wrote on a sudden impulse, but after long and careful thought; to whose seriousness we cannot always climb with pleasure; who played so little with the world.