have to say, it's not an easy theme, imo.
thus said, i think all the entries i've seen so far don't really fit the theme. the main rule was "make a screenshot that resembles the encounter of two things.", well i can't see any "encounter" in those screenies. all i see are two well defined and divided conditions; they're not really facing each other, nor they're fighting, melting, playing with each other.
this is just my opinion and i may have misunderstood the guidelines, but when i first read them i though of something way more dynamic than this.