Going Postal Challenge ** Do not understand the goal of this mission

Ok, I find the solution on forums to finish this challenge but I do not understand how we can guess in the game that we have to take the package and throw it in the head of the engineer.
No dialogue , no indication that this person wait a package. Very strange mission without goal or explanation

Some challenges are usually cryptic.
Some redacted challenges with just a picture, and some even misleading like the one in Berlin suggesting you have to photograph the sign forbiding the use of cameras, but it’s actually something else.

From solving previous challenges or knowing their solution it becomes increasingly easier to guess the goal, but part of the challenge is to figure out the idea.


Thanks @Count.Rushmore . I would never find by myself ! Thanks for your Hitman expertise.