This is the 6275th most frequent Catalan word.
mireu
"Look" (plural imperative form).
The word 'mireu' is used here as an imperative form of 'mirar' (to look), addressing more than one person to draw their attention.
Mireu, aquesta és la foto de la meva família.
Look, this is the picture of my family.
Here 'mireu' is in the present tense, plural second person form of 'mirar,' indicating the act of 'looking' or 'watching' in the context of watching a movie.
Quan mireu una pel·lícula, fixeu-vos en els detalls.
When you watch a movie, pay attention to the details.
In this sentence, 'mireu' is again an imperative form of 'mirar,' used to instruct or ask multiple people to check visually for something.