The design of the spoon is inspired by the labors of Hercules (also see Heracles), and there are a few variations of this myth, but every Spartan warrior claimed to be descended from Hercules (Heracles).
"THE LEON NEMEIOS (Nemean Lion) was a large lion whose hide was impervious to weapons,. It plagued the district of Nemea in the Argolis. King Eurystheus commanded Herakles (Heracles) to destroy the beast as the first of his twelve Labours. The hero cornered the lion in its cave and seizing it by the neck wrestled it to death. He then skinned its hide to make a lion-skin cape, one of his most distinctive attributes."
The shield and the cape on your spoon would have immediately been recognized by the Victorian highly-educated people, both in England and America, Greek and Latin were mandatory languages to be memorized by every successful student, and they all would have known about the labors of Hercules (Heracles).
This is a superior example of the type, it does remind me of the spoons of Charles Boyton (another English silversmith who created similar figural spoons), but honestly this is a very fine example of the type. I do understand why this would have been treasured as a family heirloom (especially during wartime), it symbolizes the endurance necessary to overcome all challenges.