The cover
A periscope was present in the turret roof of both "Mid" and "Late" Tigers. It had a steel cover.
This is the cover on the "Late" Tiger of Saumur museum. The periscope block itself is missing.
The cover was flared to make it wider at the front, and it was placed on a slanted roof, giving it a complex shape. But its side walls were exactly vertical. Their front edges, indicated here, were also made exactly vertical.
Vertical lines will appear vertical no matter how you rotate the tank, no matter what point of view you take. And also, as this photo shows, these two edges will always be parallel.
Takom's mistake
The CAD images of this Takom kit don't match photos of the real periscope cover. The front edges are not parallel and are not vertical. They look obviously unlike the real thing.
Takom have not released sufficient images for me to analyse the problem, but I believe they made the side walls slanting. If that is so, then it may be possible to fix this problem by bending them into the vertical. I will update this page when I can be sure.