Body doodling is one of unique sexual expressions in Japanese pornography culture. Doodling on body originally came from a Japanese traditional game for new year's "Hanetsuki" which is played with a rectangular wooden paddle called a "Hagoita" and a brightly coloured shuttlecock made out of seed of Sapindaceae. When a person missed the shuttlecock, sometimes doodling on the face with ink is carried out as a punishment.
In Japanese pornography culture, body doodling is usually used for a genre of public toilet woman. Public toilet walls are usually messy with a lot of doodles. By copying that, and regarding the woman as a sexual toy, body doodling is carried out with sexual slang and drawings.
That first image. Is that screenshot from a new episode of Highschool of the Dead? Or is it from the OVA episode (Where they spend the day at the beach)?