Open the computer molecular model titled 1-Bromo [2.2.1] bicycloheptane LUMO at the book's website for the lowest

Question:

Open the computer molecular model titled "1-Bromo [2.2.1] bicycloheptane LUMO" at the book's website for the lowest unoccupied molecular orbital (LUMO) of this compound. Where is the lobe of the LUMO with which the HOMO of a nucleophile would interact in an SN2 reaction?