These words come to mind as underscoring the capacity of this unlikely comparison to draw out some insight through analogical reasoning or mapping of the source domain (the orange) onto the target domain (the lemon) or vice versa.
- creative eccentric / offbeat / extra-ordinary
Each one of these positive adjectives alludes a contrast between two opposites, states, or realms. That tension between realms evokes the disparity between the domains or 'orders' of your comparison. They highlight the positive nature not only of this comparison, but of distant comparisons in general, which force a shift in perspective.
Words that highlight instead the playfulness of a distant comparison:
- 'playful' itself (not good for the apple/orange contrast because that example in particular is cliche)
- sprightly (similar to refreshing)