First you might notice is the runtime; Netflix's trailer is 2:13 while the original is 2:44, definitely some fat-trimming there. But even without the shorter runtime the original feels like it's much, much longer than it actually is, likely due to how many times it stops the action to show a plot point, as if they have any time to actually slow things down and build tension (spoiler, you almost never have that kind of time in a trailer). The trailer focuses less on Freeman's struggle with his change and his destination and more on the danger surrounding him on all sides, all while only suggesting once that he's been bitten and is doomed unless he finds a cure. The entire setup with his wife has also been scrubbed, instead devoting more time to the world around Freeman and his daughter. Another big change is the relationship between him and the young boy he teams up with. The original suggests that the kid's father has become a zombie and subsequently killed (and maybe Freeman is around to witness it?), so Freeman throws him a bone and offers him to tag along. The Netflix trailer instead shows Freeman saving the boy from a group of murdering humans, establishing a more dynamic relationship between the two of them.

It's normal for a film or TV show to come out with several trailers before its release, but it's rare and fascinating to see a trailer released for the same film by two different studios. It really goes to show you how effective a trailer can be and how differently a story can be told based on what you choose to show and how you choose to show it.

MAKING A BAD MOVIE BETTER.

Your film can be a steaming pile of garbage, but if your trailer is good enough the audience will never know. Take, for instance, the critically panned Battle: Los Angeles.