It is not a flip button... In the Inspector, next to pcb layer, you select which side of the board you want the part on. If the part is on the bottom and you want the move it to the top... select top in the combo box and it moves to the top of the board.
When you viewing from the bottom and drag a part on the the board, you are placing the part on the bottom of the board. The side you are viewing from is the side the new part will be placed on...