This is a command being quoted, and in nearly every line here it is followed by 하다 or 그러다: the seniors tell me to sit in the middle, they said to flip it often, tell him to eat. Dropping the usual 고 before 하다 is ordinary spoken shortening of 으라고 하다. Standing on its own it is also the blunt written command of captions and slogans, as in the caption about holding the reins and keeping balance.
Register: casual speech when quoting; terse and formal in captions