Theory:

     Across the street was another restaurant. It was not so fine as the one on Broadway. The people who went there were not so rich. Its food was not so good. Into this Soapy took his old shoes and his torn clothes, and no one stopped him. He sat down at a table and was soon eating a big dinner. When he had finished, he said that he had no money.
 
     “Get busy and call a cop,” said Soapy. “And don’t keep a gentleman waiting.”
 
     “No cop for you,” said the waiter. He called another waiter.
 
     The two waiters threw Soapy upon his left ear on the hard street outside.

     He stood up slowly, one part at a time, and beat the dust from his clothes. Prison seemed only a happy dream. The Island seemed very far away.
Explanation:
 
The next scene takes place in front of an ordinary restaurant. Soapy saw a restaurant across the street. The restaurant was not as large as the former Broadway "high-class restaurant". This was a local restaurant with reasonably priced dishes for middle-class people. Furthermore, the food in the ordinary restaurant was not as good as it had been in the previous restaurant. As it was a normal restaurant, he stepped inside the restaurant with his damaged shoes and torn clothes. After seeing his dressing, no one stopped him. While reading the story, one can distinguish the two types of restaurants into which Soapy visited. The person's look was valued in the first restaurant; therefore, he was sent away. On the other hand, when he stepped inside the ordinary hotel, no one bothered about his appearance.

Soapy sat down at a table and ordered a big dinner. 'He ate beefsteak, flapjacks, and doughnuts'.* When he finished his dinner, he told the waiter that he had no money to pay the bill. Soapy told the waiter to call the police immediately for cheating them. Soapy also stated, "And don't keep a gentleman waiting," implying that he wanted them to hand him over to a cop immediately.
 
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Soapy ate beefsteak and doughnut*
 
The waiter said that calling a cop was unnecessary, and he called another waiter to accompany him. The two waiters threw Soapy outside. Soapy's left ear hit the pavement when he fell on the road. Soapy carefully rose up, one section of his body at a time, and brushed the dust off his clothes. For him, prison seemed like a wonderful dream. But, the island appeared to be a long way away from him. The statement does not refer to the distance, but it does imply that getting into the jail was difficult because he had failed in his three attempts.
 
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Soapy fell on the hard street
 
Meanings of the difficult words:
 
S.No
Words
Meanings
1
Gentleman A polite or formal way of referring to a man
2
BeefsteakA thick slice of lean beef, typically from the rump and eaten grilled or fried
3
FlapjackA sweet dense cake made from oats, golden syrup, and melted butter, served in rectangles
4
Doughnut A small fried cake of sweetened dough, typically in the shape of a ball or ring
Reference:
National Council of Educational Research and Training (2007). An Alien Hand. The Cop and the Anthem- O. Henry(20-29). Published at the Publication Division by the Secretary, National Council of Educational Research and Training, Sri Aurobindo Marg, New Delhi.