This excerpt is from an autobiography written in an informal style. In this segment, Phil Knight relates that he told a Japanese partner that his company, Blue Ribbon Sports (now known as Nike), had an office on the East Coast of the United States, before they actually did. He therefore had to send his most trusted employee, Jeff Johnson, back east to create one as quickly as possible. Johnson loved Los Angeles, however, and had no personal interest in moving to the other side of the country.
So, Knight is trying to convince Johnson that living on the East Coast is not so bad. He is presenting different perspectives about Boston, i.e. different angles:
a particular way of presenting or thinking about a situation, problem, etc.
We need a new angle for our next advertising campaign. [OALD]
One angle specifically is of fall foliage, foliage referring to leaves on trees and other vegetation, and fall referring to the autumn, the more common name for the season in North America, but which fell out of use in Britain long ago.
Specifically, fall foliage (or fall color) refers to the color of woodlands in the autumn, a mix of intense reds and yellows. The change in leaf color occurs everywhere there are deciduous trees, including Los Angeles, but is more intense in colder climates (and where there are more such trees). It is particularly associated with New England, thanks to Robert Frost and others; "leaf peeping" is a major tourist attraction. So, Knight is trying to encourage Johnson by pointing out that living in Boston, he will be able to enjoy the fall foliage.