Ritsuka hadn't been along for Arthur's little hunting trip--really, she only goes with the Servants if they ask her to or if she's needed to help support or coordinate things. But she happens to be passing by the area near the taskboard, and spots him as he's hauling in his drops proof of completing his tasks.

"Looks like you've been busy, huh?"

Although... just how many of those did he kill, anyway??