Is flip summon considered a normal summon?
A flip summon does not count as a normal summon. For this effect to activate you would have to summon it from your hand in face up attack position (a normal summon as stated).

It is not specifically stated in the rules as such but the implications are made by statements mentioning flip summoning as many times as you want and that a flip summon does not take up a normal summon.

Source: Flip Summon wiki