About this detail of the Tiger
The Tiger 1 was designed with a heavily armoured cupola for the commander. Armour thickness was mostly 75 mm. Unlike earlier German cupolas which had movable visor covers, this one simply had five narrow vision slits. The prototype turret had internal armour shutters for the slits, but they were not used in production cupolas.
These are the dimensions of the cupola.
[1] Survey of Tiger 250122, at Bovington museum, by David Byrden
[3] DW to Tiger 1