This is a reference to their interaction in the League Club Room.

Jacq: You really are something, Ms. Raifort!
Jacq: I can’t believe you were able to figure out where those Pokémon had been sealed away just from those old writings you found!
Raifort: Heh... It proved to be simplicity itself, once I followed the clues of history.
Raifort: But in the end, it turned out that a crook like myself could never have opened the seals. So I let a friend have the treasure.
Jacq: So you formed a hypothesis based on clues, then put it to the test. I suppose history and biology are similar in that way.
Raifort: Speaking of testing things... I was just considering testing out the effects of a certain ancient ritual.
Raifort: It just so happens that I need an adult male as a sacri—I mean, assistant. Care to help out?
Jacq: I’d love to help! Count me in!