Frequent continuity errors.
It's clear that many scenes were filmed hours or days apart and then edited together with =out consideration for whether or not they visually flowed together.
In several of the episodes, when the fired apprentice leaves Trump Tower they get into a cab in which the hack number is clearly visible; however, when the cab pulls away there is a different number on the side of the cab.
In the episode where Audrey is fired, she is seen in the boardroom and lobby wearing a dress. When she walks out onto the street and into the taxi, she is clearly wearing pants.
The businesses "created" during the series in fact do not exist. None are viable entities which exist anywhere away from the sound stages and scouted locations for them.