The periphery can also apply to vision (peripheral vision). Things on the periphery are usually seen from the corner of one's eye. Fiona is skeptical of the people and places that make up the periphery because they're (their intentions are) not within clear vision ("Have them forge you a pedigree ... run it if you want ... but not with me, 'cause I don't appreciate people who don't appreciate").
The periphery can also apply to vision (peripheral vision). Things on the periphery are usually seen from the corner of one's eye. Fiona is skeptical of the people and places that make up the periphery because they're (their intentions are) not within clear vision ("Have them forge you a pedigree ... run it if you want ... but not with me, 'cause I don't appreciate people who don't appreciate").