Freezing seawater does not turn the ocean into a uniform block with salt distributed everywhere in the same way. Ice crystals and the salty liquid between them follow different parts of the story.
The National Snow and Ice Data Center’s sea-ice guide describes concentrated brine forming during freezing. Some is expelled to the surrounding water and some remains in pockets between crystals. Brine can later drain through channels, while meltwater can flush remaining brine from older ice.
Sketch two materials, not one colour
On a simple diagram, shade solid ice differently from liquid brine. Add arrows for possible drainage rather than drawing salt grains evenly scattered through a solid block. Label the drawing as a conceptual sketch, not a microscopic reconstruction.
This distinction helps when reading a statement about ice salinity. Ask which ice, at what stage, and by which measurement. A description of newly formed ice should not automatically become a description of ice that has survived several seasons.
It also raises a second question about the water around the ice: where did the expelled salt go? The source explains why exchanges between ice and ocean matter beyond the outline visible in a photograph.
A white surface alone does not reveal those internal passages. The interesting process includes liquid moving through something we casually describe as frozen.
Editorial illustration from this site’s image library; not documentary evidence of the example or object discussed.