Thread's super old, but relevant nevertheless, I had some thoughts on this.
Fi shyness isn't actual shyness, but selectiveness. Gamma types need a gradual "warming up" in any type of human relation, we're not on a merry level instantly (yes yes SEE-Fi's Fe is 4.5D but it isn't VALUED i.e. considered with conscious efforts. They are always merry when they have to be but in private... oh man). We value Ni, so long-term dedication determines our choice of interaction, and SEE-Fi's Ni is more pronounced than SEE-Se's, that's important. So nothing too casual here. Meanwhile, SEE-Se is the opposite of shy, sporting very prominent democracy. See @jaded whore. Te HA creates a focus on how necessary a relation is to one, hence SEE-Fi will be reserved until decisive while looking out for someone who's also keen on a more pragmatic style of interaction.