Commensalism is a type of symbiotic relationship where one party benefits and the other party is not significantly affected. A hermit crab takes over a discarded shell of a snail and uses it for his house. The hermit crab benefits and the snail are not affected - it's already discarded the shell and is nowhere around.
She's applying emphasis onto the word. Christie wants the word dramatic to really be out there. Christie is implying that __ is very dramatic. This repetition makes the word stick in our heads as the main focus.
