The ice cube analogy would work fine if all the ice in the Arctic was subject to the same melting action as the cube in the glass. In an area like the North Atlantic, that is very much the case. However, in an around Greenland and the Canadian archipelago, the physics are quite different. Arctic currents take much of the water poleward, bypassing much of ice floes. Less ice is contacting the warm waters, than when the sea ice extended much further southward into the Atlantic. Consequently, summer sea ice is very likely to slow its decline. Winter sea ice has not reach this point, and may continue its current trajectory or even increase.
Any case in which surface area (or extent) declined, while volume increased seems like a stretch. Ocean water is coldest at the surface, -2C in an ice/water slush, warming in depth, to 4C at the bottom. The likelihood of water freezing at a lower depth, in warmer water, while surface water does not, defies the physical properties of the oceans.