Focus on the first seven seconds. What did you think and feel? How did you "read" the other person? (Para. 2)
Meaning: Pay special attention to the first seven seconds. What did you feel and think? How did you understand the information about the other person?
focus on: pay attention to; have as its main point of interest
We must focus on our sales force as the chief means of improving trade. 作为促进贸易的主要手段，我们必须加强我们的销售队伍。
This year our meeting focuses on the question of children's rights. 今年我们的会议集中讨论儿童权益的问题。