I'm interested in thoughts on this. It makes sense to me, so... in this analogy Fi is the sea house and Se is the sea, in other words reality. That is how I take it.
There is an interesting part in this book Personality Types.
Such types can end up feeling like Kevin McCarthy in Invasion of the Body Snatchers, faced with two bad choices: they can go to sleep, let the pods take over, and wake up happy to be programmed, or they can fight to stay awake and spend the rest of their lives resisting cooptation.
When isfp develop extraverted sensation it takes them out of this either or dilemma. They begin to see that their potential dictates outward responsibilities. An image given to me addresses this situation.
If you live in close contact with your inner world, it's a lot like living by the sea. You can get flooded unless you can build a structure to meet your needs. Your first instinct, however, is to build the kind of house townspeople live in, because that's the kind of shelter others will help you construct. This is precisely the kind of house that will be ruined when the tide rises. For a while you think, "I should have built a better townhouse" but gradually you reject others advice and you live without structure,
Why not build the kind of house that will serve your actual needs? Build the kind of house that fishermen build, one the water can go through without knocking it down...
Well developed isfp live, as it were, between the sea and the town, doing what they need to do. In consequence, their creations, their choices, their way of being...