I always pictured a comet to look sorta like a large very dirty blob of frozen icy like stuff composed of water, methane and other solidified gasses looking sort of like a snow cone of shaved ice that fell into the mud.
I expected it would be somewhat irregular shaped but it would have gently rounded edges caused by any sharp irregularity evaporating or "boiling off" from the effects of the solar radiation and solar wind.
I expected to see some impact craters and there are some but I expected to see the edges of them rather rounded off like one would see if they dropped a ball bearing into a bowl of gently sifted flour.
The very distinct, sharp, rock like surfaces shown all over the body of the comet in the photos was not what I expected to see.
Having read a bit about this comet, it's density is very low signifying a lot of open or very loosely compacted material. This was verified by reports from the lander which was measuring the strength of the radio signals from the orbiter. As the orbiter passed around the back side of the comet from where the lander is resting the signals did not decrease as much as they would if the comet was more solid.
Some of the photos taken as the comet approached the sun show the outgassing from the surface but it isn't at all like the surface was evaporating. Rather, it shows localized jets of gas being expelled from vents.
Check them out in some of the more recent photos in the links I gave.