I think image directly relates to the person not the activity. There may be certain sports that attract a certain person with a high degree of conceit or narcissism, surfing, wake boarding, skiing (maybe) snowboarding (maybe). Some of those sports attract a younger group that preens itself for the attentions of the opposite sex.
With scuba diving I think it's an older crowd so that activity is diminished by a more mature attitude. I think diving is a more mature sport just by default because of the responsibility involved.
As far as style, I don't think many people really know enough about scuba (I'm thinking beachcombers) to know what they're looking at, or what's in style and what's not. I actually don't think there is a seasonal or "latest" style in scuba. Maybe on a boat full of other divers somebody will stick out of they have something unusual or all brand new (usually means a new diver), or perhaps if they are using vintage gear.
I think divers in general don't worry about impressing people, they just want gear and configurations that work, whatever that combo may be.