In order to portray the characters vividly and convincingly the author of the analysed passage resorts to the following devices:

  Lexical:

Metaphor : speaking about Connie - “her face gleaming with a joy that had nothing to do with Eddie

or even this place;”, “" She always drew thick clear lines between herself and such girls”, “she wasn't interested, rolling her eyes to let her mother know just what she thought of it.”

Irony: Arnold  Friend, who wasn’t  a friend, just pretending.

simile: to describe and emphasis Arnold’s Friend features - “He took off the sunglasses and she saw how pale the skin around his eyes was, like holes that were not in shadow but instead in light. His eyes were like chips of broken glass that catch the light in an amiable way.”,  “hair that looked crazy as a wig”, “He spoke in a simple lilting voice, exactly as if he were reciting the words to a song”,” reddened slightly as if the veins grew too close to the surface of his skin”, to describe and emphasis Connie’s features - “…her laugh, which was cynical and drawling at home—“Ha, ha, very funny,”—but highpitched and nervous anywhere else, like the ringing of the charms on her bracelet.” , “She put her hands up against her ears as if she'd heard something terrible, something not meant for her.”, “inside your daddy's house—is nothing but a cardboard box”

Hyperbole: “Even his neck looked muscular” – to emphasis Arnold physical superiority.

antithesis – “June did this, June did that, she saved money and helped clean the house and cooked and Connie couldn't do a thing, her mind was all filled with trashy daydreams” 

to emphasis the difference between ideal daughter and bloody-minded one.

Symbol – her Home, was like a symbol of her, she was standing in the doorway and deciding what to do, it was like a crossover from the childhood to adult life.

Personification: “His smile assured her that everything was fine.”, “hair that drew anyone's eye to it” as for Arnold

Graphic: 

Italics: "He's kind of great," Connie said reluctantly. "Listen, that guy's great. He knows where the action is.", "Him, he's crazy,", “ —I mean, don't fool around,", Arnold made such remarks to show his superioty and poverty.

The author presents usage of colloquial  speech ( “dope”,” You're cute."). also some dialect words ("Toldja I'd be out, didn't I?", "Don'tcha like my car? New paint job,", "Can'tcha read it?", Can'tcha see I'm your own age?", "Don'tcha know it's Sunday all day?) in the speech of main characters. From the  Connies side it is obvious as she is a teenager, but from the Arnolds ( as he is at least 30) it emphasis his ignorant, ill-mannered man, pretending to be like teenager.