A periscope for the loader was added to the Tiger's turret roof in March 1943. This allowed him to help with an important task; spotting exactly what the tank hit when it fired.
The periscope was the same kind [2] as in the crew hatches in the hull [1] and it had a similar 15mm steel cover on the turret roof.
This plan gives the location of the periscope on the turret roof.
When the turret was redesigned, a new cupola with short, slanted periscopes was introduced. The loader's periscope position was completely redesigned to use one of these. A new cover with a wider field of view was fitted. This diagram shows the new cover.
[1] Der Panzerkampfwagen VI und seine abarten, Walter J. Spielberger, Motor Buch Verlag