Buffy's suggestion about arranging a meeting is good advice. Outlining your aspirations will mean it will be easier to ask for a letter of recommendation later on.
Networking is the other aspect to this question. Even though you are being "supervised" by the head of the lab through his PhD student and junior professor, networking is a useful skill that you might want to work on while you have the opportunity now. Find out which meetings, activities that your head of lab goes to. This might give you opportunities for informal discussion about your project and for him to get to know you.
Consider developing your "professional identity" online as well. This may be useful for you as you network with your future university and developing a strong presence. Sign up to Twitter, ResearchGate, Mendeley, etc. Participate and engage with the various meetings of the department and lab - Academic Skills article, Manchester Uni
I liked this light-hearted article about social networking by Thesis Whisperer. Jennifer Streeter's article is also impressive.
Remember, if you can meet and get to know your future colleagues from your other university, you would be light-years ahead from the competition. If they grow to trust and appreciate your work, they would be bending over backwards to help get you across to them. Academic excellence is important and so is the recommendation letter, but if they like you, it does matter as well...