This image is not in the trailer (haven't seen the documentary). Big cruise ships do (did) visit Venice as we can see from the trailer, I am not doubting this fact.
Question: Is this image real, did this exact cruise ship came to Venice the way it is pictured in the image?
Update: Got this image from private chat group claiming it is real. Although no one is claiming it is real in public, it seems relevant to find out if it is photoshopped, i.e.: added a big cruise ship just behind the church, for the purpose of exaggerating the effect of the documentary. I understand every cover photo is retouched, as noted in the comments the sky looks like painted.