It's an ambiguous scene.
The redheaded person is holding a sheathed sword in a way that suggests that she (or he) is about to lift it horizontally and present it to the green giants.
The two adult giants are just standing there, possibly listening to the redhead.
A juvenile giant seems to be climbing both the rock face and the black-haired giant.
The bald giant is holding a small tree trunk that has been sawn off at both ends, and appears to be bloody at one end.
It's entirely possible that the giants are a family group standing on their own land. The bald one has been pounding something with the tree trunk (maybe an Englishman's bones, to make his bread, as the poem goes) while the child climbs the rock wall and his or her mom. Now some human (or elf, I suppose) has arrived to make an official presentation of a sword, possibly to reward or commemorate some service rendered by the giants.
