You might think this is a summer vs. winter picture. Nope, this is an evening and morning picture.
I took the top picture late evening on my way home, with the midnight sun shining on the harbor.
The next morning on my way to the airport, I took the bottom picture with the harbor covered with all this ice.
This happens overnight when the huge icebergs have broken out from the mouth of the icefjord.
The icebergs brakes from the glacier front 70 kilometers from Ilulissat. Then they move up to 40 meters per day, floating on the appr. 1000 meters deep water, until they hit the mouth of the fjord which is 250-350 meters deep. Here they get stock until they break into smaller peases or they melt, then they get pushed out with the stream out into the Disko bay. When the icebergs starts breaking it sounds like thunder, and can change the harbor picture overnight.