I think that’s exactly why he had that reaction.
If the King’s father died, the next King need to be strong to inherit the title suddenly. To take care the job asap. The same with any Dukedom or County, the heir (whichever gender) need to stand straight to take care of whatever their father left behind.
It’s a bit different with Queen/Empress. It’s not even the former Empress who died. Harshly speaking, he’s a stranger if we talking about work and responsibility. She doesn’t have to pretend to be strong in the face of tragedy.
And I think what makes her more terrifying was because she talked about “Angenas Works,” not the Empire related thingy. She ain’t worried about the balance in Duke power or something.
It was more like, she ain’t the heir of Angenas, why is this job more important than her own father death?
I’m not saying she is the worst. Actually I agree with the commenter after you, this woman really coolheaded, excellent and ruthless leader. She’d do much better becoming the Duchess (as in house head) rather than Empress. I bet Dullac Lombardi would have his best rivalry-match with her than her father.
I get that it's to move the story forward, but I wonder if the guy would have the same reaction if she was the king and had to push forward with whatever they were doing. Would he describe her as a stoic leader who's strong in the face of tragedy........I just love an ice queen(づ￣ ³￣)づ