This is the 12880th most frequent Spanish word.
parecían
"Parecían" means "they seemed" or "they appeared" in English.
Here, 'parecían' conveys a metaphorical resemblance observed at the moment being described.
Las luces de la ciudad parecían estrellas en el cielo nocturno.
The city lights looked like stars in the night sky.
This use of 'parecían' describes the impression or illusion created by the shadows in the painting.
En la pintura, las sombras parecían moverse como si estuvieran vivas.
In the painting, the shadows appeared to move as if they were alive.
In this sentence, 'parecían' is used as the third person plural imperfect indicative form of the verb 'parecer', indicating an observation or impression about the children's mood in the past.