User blog comment:ProfessorKilroy/Sony Announces "Venom" & "Sinister Six" Films/@comment-166-20131213135849/@comment-4651179-20131214190921

Because they had to show the actor's face. The same reason why Captain America has to loose his helmet at soem point of the final battle, even though you can still see he is Chris Evans when he has it. Or why he and Iron Man appeared without their faces covered in most of their movies' posters.