Perhaps it is something to do with "Perigean Spring Tides". Tides are usually fullest on a new moon or full moon. But when the moon is also further away or closer to Earth than normal (i.e. at the perigee or apogee of its orbit about the Earth), the tides can be greater or lower than usual.
The Moon was at apogee on 5 December 2015 (http://www.basicastro.com/apogee-perigee-2015.html)
It was a New Moon on 11 December 2015.
Maybe the photos were taken around 8th to 11th December, rather than the article date of 17 December?
Google Translate translates some of the comments below the article as being something like "This happens every year."
Wikipedia article on "Perigean Spring Tides", sometimes called "King Tides": https://en.wikipedia.org/wiki/Perigean_spring_tide