About this detail of the Tiger
The second type of cupola used in Tiger 1 had seven periscopes and a recessed hatch lid. The hatch was opened by swinging it to the side rather than raising it; the hinge was located on the left. A rail was welded on top of the periscope covers, to carry an optional anti-aircraft MG. At the front, a gap in the rail allowed the hatch to swing forwards.
Almost immediately after production began, the layout of the parts was mirrored so that the hatch swung to the rear rather than to the front. I have seen photographs of only 2 Tigers with the original layout, including Tiger "C11" of III/Panzerregiment "Großdeutschland".
It was apparently possible for rainwater to collect in the hatch recess. During the production run, three drain channels were added to the cupola shell, at these specific positions.
Eventually these channels were moved to be halfway between the periscopes. This was probably to simplify manufacture.