Removed "Ultramarines" tag, the insignia on her shoulder doesn't look like Ultramarines symbol (upside-down omega).
Making a big assumption here that average taggers on this site knew what Ultramarines meant to begin with. Whoever tagged it probably did it in a similar fashion to marking any robot with antennas as a Gundam.
Considering that there is an actual space Marine chapter called the Carcharodon Astra, or space sharks. I'm so very happy that the connection was made, it is so fitting
It's in the comment, read the comment Also, the bloop servo-skull is really cute Edit: It's also probably the chapter master, Tyberos, because of the armor