so if I want a bigger island with the same outline I would have to use a higher resolution or a lower resolution?
You may want to provide examples or more information about what you are asking. I'm not sure what you're talking about
If you want a bigger Island, you want a higher resolution. Look at it like your pixelart software: If you want to draw a small shape, you use less pixels. So the more pixels you have available, the bigger your sprite will be.
