The vase is placed right on the edge by the door but if you are looking at the stove you don't look left and see it so you don't know it's there (what vase?)
When you walk in and stop it is directly behind you
Oracle indicates as she says it - this causes Neo to turn left and look behind - his left arm catches the vase and sends it over
If she hadn't have said anything then no, he wouldn't have turned to look so wouldn't have broken it .
