Attack on Titan Final Season Part 2 airs weekly right here on Crunchyroll every Sunday, though the series will be on break next Sunday due to special programming on NHK with the next episode on April 3.
The first two pieces of art come from animation director Fumihide Sai and are key animation frames of both of them.
He also runs a YouTube channel about Japan stuff called TheDoctorDazza, tweets at @DoctorDazza, and posts photos of his travels on Instagram.