Minding Your Manners
Another rule of common courtesy has to do with basic manners. It's alright to make comment about things that might be visually appealing to you within the area where the interview is being conducted, but the age-old childhood rule of “look but don't touch” is applicable. Nothing is more intrusive of the personal space of an interviewer than an interviewee who touches their things. Keep your hands to yourself and demonstrate the common respect that you'd expect if the situation were reversed.
Some sage advice that is often repeated by our elders is that we were born with two ears and one mouth, and the truly wise person uses them proportionally. That's hard to do in an interview where you are trying to convey every good point about yourself that you can think of. But the lesson of the advice is to listen closely to what is being said or asked by the interviewer. It's good practice for those times in the future when you are in court. When asked if you know what time it is, you don't automatically volunteer the time of day.
You answer “yes” if you know what the time is, and “no” if you do not. By the same token, answer the question that is asked honestly, and don't volunteer the answer that you think the person wants to hear. Listening to what is being said or asked is another one of the basics in displaying respect for other people.