The correct [CONNNECTOR] to fill the blank is

"The task is a breeze for people ___________ hard for machines"a) moreover (in addition to what has already been said; furthermore)b) furthermore (In addition; moreover) c) since (After some point in the past) d) despite (In spite of; in opposition to all efforts of; notwithstanding) e) though (although; However; nevertheless)Breeze = (Informal) Something, such as a task, that is easy to do.

e-

The task is a breeze for people though hard for computers. Upon using "though", the author hints at some information that offsets the information in the main clause, meaning that flipping upside down pictures comes naturally easy for humans while for computers the task can't be figured out through the current levels of algorithmical artificial intelligence