Much has been said of how Andrew J Robinson's performance of Elim Garak in his initial appearance was a spontaneous decision he made the first time he saw Alexander Siddig in costume, but it's fun to bear in mind that this must have been true from an in character perspective as well.
Like, this is Julian Bashir's first posting fresh out of med school; Garak theoretically has access to what's in Julian's academic record, but he has basically zero personal or professional history to go on.
We thus have to imagine Garak asking "all right, what is the best way to go about pumping this person for information?", taking one look at Julian, and making an on-the-spot decision that his best play is to crank up the daddy energy and attempt a good old-fashioned honey trap.
