The end of the queue

Original non-fiction-style practice text.

The exhibition's new ticket scanner admitted visitors twice as quickly as the old desk. On the first Saturday, the entrance queue almost disappeared. The manager was preparing to describe the trial as a complete success when a gallery attendant asked her to visit the cloakroom.

A long line now filled the corridor there. People who had previously checked a large bag while buying their tickets were being sent straight inside and then redirected. The cloakroom had only one worker, and the scanner's information screen did not mention the bag rule. Families sometimes reached the first gallery before learning that they had to return.

The manager added the rule to the arrival message and stationed a helper before the scanner. At the end of the weekend, she reported both admission time and the time taken to reach the exhibition rooms. A faster doorway had been useful. It had not automatically made the whole visit easier.

Explain, using your own words, three reasons why the faster entrance has not removed all the waiting.