Any Se type is probably going to care about fashion or presentation somewhat, even if in the back in their mind. In the Jungian sense, Se considers the worth of objects from an extrospective/impactful point of view. In a way, they see things the way they think things are meant to be seen, or how a majority sees them. He described them as sort of seeing things through the lens of the "present age". In terms of their presentation, they might be "trendy". This would be the most beneficial approach for them, in getting what they want. The Se dominants especially. He contrasted Si and Ni as being more personal or timeless and even confused in how they presented themselves.
Introverted judgement is contrasted as an attitude that scrutinzes and judges the external objects first. So they're not trendy exactly. Yet they're not unconsciously seeing things differently than Se either. They see many of the same opportunities, but judge it more often. Even still, their second function still wants to be relevant and part of the environment somehow. They'll just offer their own take on things. Maybe a bigger emphasis on personal comfort or expression, but with the hopes that it might have some actual effect. They wouldn't mind being seen as cool, or maybe they're artists and want people to follow their advice (and start trends themselves.. which might be the case with a lot of ISFPs more than ISTPs).
If they don't care at all, it'd more than likely be a conscious choice. Which.... is how I am today. When I was in highschool, I cared more. I didn't have any money, but I remember borrowing a lot of clothes then -- and I knew what I probably should borrow. And I knew what I had myself wasn't good enough. I knew what would make me look like a geek if I walked into a room. I'm not that stupid. Nowadays I just don't give a shit, but I still know. I'm too aware of what's going on to be truly careless.
edit: Damn, I must be bored. This was too long.