The term 'pharmaceutical' refers to the creation and sale of medicine. Smile, make eye contact, and give yourself an air of confidence. Whenever being allowed to relax a little in an interview, especially when being invited to 'talk shop,' you want to come across as being able to talk the talk and walk the walk. Research the body language of someone confident and relaxed in a seated position. Practice those positions. Aligning the words you say with the body language you convey will go a long way towards delivering a successful interview.