The fact that Larys chose a firefly as his personal sigil. Fireflies produce light like the hightower but they’re miniscule and insignificant in comparison. He’s signalling his allegiance to Alicent but also positioning himself as so far beneath her, like he’s saying: I’ll crawl and flutter for you, my queen. You could crush me if you wanted. But of course fireflies are pollinators, and Larys has compared Alicent to a flower, ‘a rare bloom.’ (Also fireflies produce light to attract a mate.) So there’s the implication that he’s sexually attracted to her and that he wants to feed on her (exploit her) to his own benefit. But then the flower also needs the pollinator to do what they can’t. They’re symbiotic in the end.
‘If it is an eye you want to balance the scales, I am your servant.’
‘The day will doubtless come when I require such a friend.’
Who wants to bet Larys will be the one to supply the poison that does the thing in the end, and then he takes the fall for it when the Hour of the Wolf dawns. An eye for an eye, a son for a son. A balancing of the scales.