The article states --
Melted nuclear fuel debris is seen attached to pillars, walls and the ceiling, and accumulations between approximately 40 and 70 centimeters thick are piled up and cover the whole floor.
But nothing in these pictures give me any take on the thickness of the melt.
TEPCO's report is better and more detailed
----------------------here is an earlier story on the same photoshoot
In a PDF handout by TEPCO around Ja 31 2018 I found this diagram quite helpful in explaining what we are looking at.