Slash Film has the run-down on the descriptions:
Guardians of the Galaxy 2:
Baby Groot sitting in a seat on the Milano as Star-Lord yells back “Groot, put your seatbelt on!”, a shot of Rocket with a gun, another shot of Rocket flying a ship and talking about how they’ll really be able to jack up their prices as two-time galaxy savers.
Baby Groot in red Ravager outfit walking slowly with his head down, his steps squishy. H seemed sad. He gets close to a cell holding Yondu and Rocket. Yondu yells “Hey Twig, come here.” After Baby Groot walks over, Yondu and Rocket explain to him how to break them out. Yondu takes his Ravager badge off his coat and gives it to Baby Groot and tells him to take it up to a room where that will open a drawer with a key. Groot takes the badge and puts it on his head, all sad. Rocket then interprets that Groot thought he wanted him to wear it as a hat and that made him sad because he doesn’t like hats and thinks people think he has a funny-shaped head. Rocket asks Groot if that’s why he is sad.
A shot of Cate Blanchett as Hela from Thor: Ragnarok, holding Mjolnir from the top, with the handle horizontal and extending away from her. Several shots of Thor and Hulk, both in gladiator garb, as seen in EW photos. Also, a shot of Thor putting his helmet on and turning side pieces of helmet from horizontal to vertical.
Captain Marvel concept art:
...an action pose of her in the air, about to hit someone.