Why does it say ellos in sentence two, does it not refer to las maletas?

Hola Siv Joanna

I know why it may be a bit confusing. The "ellos" comes straight after talking about the suitcases (maletas). But this "ellos" is referring to the Check in staff; we are using a general "they"; literally we are saying: "and they assign/allocate us a seat". 

Hope it makes more sense now.

Saludos

Inma