The influx of people and the difference in the girl represent the passage of time and the character's repeated attempts to find a bed for the night. The original girl passes by and bids him goodnight.
On the train, the fan with the newspaper is asked how Ipswich (football club) are doing. He responds: "they're losing, one down". He's asked again and repeats "one down", but the Football Half Time score shown in the close up of the paper states that Ipswich were winning 1-0 against Fulham.
About 3/4 thru the film, Alfred Lynch returns to the jazz club, where he meets one of his girlfriends backstage in the seemingly empty venue. He suggests "a bit of a dance" and they move to the dance floor, where suddenly a band is playing. In the next two shots a crowd appears on the dance floor and the club is full in about 5 seconds! His girlfriend then suddenly changes both hairstyle and clothes from one shot to the next. Maybe the continuity girl had the day off.