How does Dannie Abse indicate the contrast between himself as a boy and himself as a man in the second stanza? Use highlighter colours to indicate ‘before’ and ‘now’

The journey to Cardiff seemed less a return than a raid
on mislaid identities. Of course the whole locus smaller:
the mile-wide Taff now a stream, the castle not as in some black,
gothic dream, but a decent sprawl, a joker’s toy façade.

What are the connectives which help to indicate the contrasts?
What use does Dannie Abse make of hyperbole, and to what effect?