As Ray Palmer approaches in his ATOM suit, Caitlin says "it's a bird," Cisco says "it's a plane," and Felicity says "It's my boyfriend," a play on the traditional Superman catchphrase. Brandon Routh who plays Ray Palmer played Superman in Superman Returns (2006).
After Barry reminds everyone they're up against a metahuman killer that can control a swarm of bees, Ray Palmer says: "Cool. I mean awful". Barry and Felicity uttered those exact words during the Flash/Arrow crossover.
Brie Larvan wears a jacket that resembles a honeycomb, and her dress' neckline has hexagonal patterns, indicating her relationship with the bees.