While Luke is serving customers at the diner, Kirk and two young boys come in, ordering old fashioned soda shop drinks. It soon transpires they were sent by Taylor, making a point how necessary such a soda shop is, which Taylor wants to install in the space next to the diner, owned by Luke. Kirk already works for Taylor, and the two boys are presumably in his Boy Scout troop.
Egg Cream: Previously discussed.
Black Cow: Traditional name for a root beer float, which is root beer with vanilla ice cream. In some areas, the ice cream has to be chocolate in order to be called a black cow, and others say brown cow instead. (Root beer is a North American soft drink made using the root bark of the sassafras tree, or the sarsaparilla vine, Smilas ornata). Frank J. Wisner, owner of Colorado’s Cripple Creek Brewing, is credited with creating the first root beer float in 1893. The North American fast food chain A&W Restaurants are well known for their root beer floats.
Chocolate Phosphate: Traditional soda fountain drink, which is chocolate syrup and acid phosphate added to club soda. Acid phosphate is a mixture added to drinks which gives it a slightly tart flavour, and aids carbonation – a partially neutralised solution of diluted phosphoric acid made with salts of calcium, magnesium, and potassium. It’s recently come back into fashion as a mixer for soft drinks and cocktails.
Note also in this scene, references to ham on rye sandwiches and Coney island, previously discussed.