This is an interesting question to ponder. I suppose that the physical space in which the jury has to deliberate may subtly or unconsciously influence the decisions that they make. If the jury room is uncomfortable, drab, or simply not a pleasant place to be, the jurors may feel more eager to quickly come up with a verdict so that they can leave.
If it is near the end of the workday, a distracted juror may have their mind on getting home without getting stuck in rush-hour traffic. Some jurors may also want to come up with a verdict before the end of the day rather than face the prospect of coming back the next day for further deliberation.
The weather can also have an unconscious effect on people. Perhaps the idea of being stuck in a drab jury room on a beautiful sunny day might influence a juror's decision-making process. Maybe a dreary, rainy day can influence a juror's mood. Many courthouses are in old buildings that may get uncomfortably hot in the summer or cold in the winter. This can also affect the comfort and mood of a juror.
In short, there are many parts of our surroundings that can have an unconscious effect on the way we make decisions every day. This could all be a factor when dealing with people in the process of making an important decision, such as jurors deciding on a verdict.