A couple of comments:
1) One year in the arctic or antarctic is not very important.
2) GRACE data in graph is through 2017. See post above for papers on Greenland mass balance.
3) Regarding arctic sea ice, this year so far looks unremarkable to me. Its not a big melt year like 2012, but its not far from the long-term trendline on most metrics either. (see chart below)
4) There hasn't been any long-term trend in Antarctic sea ice so smack dab on the median is as expected. Ice shelves and ice sheets are the big concern in Antarctica, not sea ice.