It't not that Els didn't want to make an effort, it was that her last-minute, half-assed packing didn't really allow for that much stuff she could use for a costume. Also her side of the room is like super messy so she could only find half her stuff. Still, black t-shirt, jeans, ankle boots and sunglasses were enough for her to be Johnny Bravo for the night. She couldn't do anything about the hair, but for that ~extra touch~ did put her hair up in a ponytail with a quiff, and stuck a comb in it.
She also tried the accent for a bit and actually mostly succeeded.