Seven often doesn't feel adventurous when it comes to food. When she first started eating, the Doctor had warned her that she may have adverse reactions because of her enhanced immune system, until her human biology completely reasserted itself. Therefore, she plays it safe.

She's not the most perceptive when it comes to things like this, so it's actually somewhat surprising she picked up on it. She looks...sympathetic, almost, either way it's a muted expression, her face doesn't quite follow her eyes.

"Which is not as simple as it sounds."