Do we know where this image was taken, and when? It is not really uncommon to see icebergs calved from glaciers near shore. I think the second image shows a larger iceberg than the first one.
The first image is an interesting photo, but I have seen icebergs as large or larger in eastern and western Greenland, Svalbard, and even off the coast of Newfoundland, than the one in this picture. I have seen them with tunnels large enough through them that the masts of 110 foot long sailboats would sail through them with ease - except for the possiblity of hundreds of thousands of tons of ice falling onto the boat from above, and others many kilometers in diameter, approachable by zodiac.
This tunnel was one of the smaller ones I saw in Scoresby Sound in eastern Greenland on August 31, 2015. Notice closely, the drone exiting the tunnel as it returns to our boat - it was raining heavily near the roof of that tunnel.
I know the iceberg that has been drifting from Antarctica since 2017, A-68C, is really huge, almost 200 meters thick, even though is is beginning to break up as it nears St George.