"Rising Five" begins with a familiar scene: a little kid insisting that he's not four, but almost five. The speaker looks closely at this little boy and sees is at once an archetypal picture of childhood and something a little less familiar.
On the one hand, the portrait the speaker creates of the little boy touches on a lot of standard-issue images of children. This boy has a mop of curly hair, huge eyes, and cheeks full of toffee; the reader can see him clearly, a figure at once solemn and a little silly in his solemnity.
But the words the speaker uses to paint this picture are strange and new. Rather than simply saying that the boy had a head of curls, the speaker describes how "the little coils of hair / Un-clicked themselves upon his head." This peculiar use of the word "un-clicked" makes meaning through sound: the sharp consonants of "clicked" give the reader an image of tight, crisp ringlets—which, if "un-clicked," must be loosening themselves, changing.
And this boy's eyes aren't merely big and wet: they're contained in old-fashioned "spectacles" which seem almost to overflow with eye. If his cheeks are "toffee-buckled," they're bulging with toffee, but maybe also glued together with toffee; the reader can hear him through his chewy mouthful as well as see him.
The simultaneous familiarity and strangeness of this little boy give the reader the feeling that the speaker is really looking at him, the way one looks when something has caught one's attention. The speaker is seeing something interesting in this little boy, something beyond the mere sweetness of a child's self-importance about his age. Both change (in the form of the "un-clicked" hair) and bodily decay (in the form of those premature "spectacles") are already here in this encounter with a child who seems too little to be linked to either. The rest of the poem will emerge from this encounter.