Even if you become invisible with a potion, you can still see your hands when you hold a map.Your'e supposed to see a floating map.

In this screenshot you can see my hands holding the map, but in the inventory screen im definitely invsible
How to reproduce:
1. Drink an invisibility potion (or use /effect)
2.Grab a map (Normal map not empty map)
3.You'll see the bug.Your hands will be visible.