The quote "keep looking up, that's the secret of life" is a statement or command?
Solution 1:
It's a command, called a hortative.
urging to some course of conduct or action; exhorting; encouraging: a hortatory speech.
(From The Free Dictionary)
It is an imperative (lacking the You in (You) keep looking up.
The imperative Keep looking up is a hortatory, serving a function in the vein of "Make a plan to vote," "Maintain social distancing," or even the simple, "Let's go!"