Stuart Hall discusses the notion that the powerful elite groups which create media create a normality that reflects themselves and their ideologies. This is representative of Antonio Gramsci’s concept of the hegemony model.
I mention this as France has had a long history of experience of immigration - tracing as far back as the 1930's. Thoughts of immigration has always been argued over globally and throughout history we have seen the media represent immigrants as violent and unwelcome outcasts.
These common views in the media therefore appropriated immigrants (which The Returned appear to metaphorically represent) as a series of stereotypes and characterized them as opposites of the (mainly) Western (or the 'living') populations.
This idea of Western populations vs immigrants can perhaps be seen in the show through how the Returned are treated as 'other'. For example, at the end of the last episode of series one, Lucy (a returned) is lit from behind pitched as a silhouette which creates distance between herself and Pierre and Thomas - creating a clear divide between them. Perhaps the harsh spotlight which shines on her could also represent the way in which the media constantly glare judgment on immigrants. Whilst she (along with the rest of the dead) physically look the same they are still treated as 'other' - just like immigrants.
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The language used to discuss The Returned is also interesting especially in the final episode. We see for instance Adele's change in attitudes towards The Returned (specifically Simone) through not just her frantic yet fearful actions but even with her language choice as she refers to the Returned as 'them'. This us of this collective pronoun could link to the episode's actual title of 'The Horde' which actually relates to a 'large group of people.' This idea of grouping the 'Returned' together reduces them again to just a collection of stereotypes. Viewing them as a group could even make them appear more intimidating which may link to immigrants usual representations of aggression. This can be reinforced with the language used to describe them in the show (again particularly in episode 8) such as 'monsters' and 'dangerous'.
Representations of immigrants as violent could be highlighted through how the dead attack the living. Not only does Serge commit several gruesome attacks in the underpass but even Simon (in the first episode) attacks a man in a diner for food and Victor (a seemingly innocent dead child) is suggested to kill Julie’s nosey neighbor Mrs. Payet.
Many people often blame immigrants for other societal issues (such as increase in crime or unemployment) which is also represented through the show. Sandrine looses her son and openly blames the Returned for everything that subsequently goes wrong. Here the living (or Western population) may represent a closed-minded society who seek to construct 'enemies' from the Returned (immigrants).
As stated before, immigrants are often seen as unwelcome which is clearly demonstrated through Pierre's bunker and willingness to 'fight back' against the dead. Perhaps even Thomas' own determination to get rid of Simon could also be representative of this.
It is important to say that I believe the show does not try to reinforce these views and ideologies on immigrants as instead I perceive this to be a comment on their treatment. The writers of the show have openly discussed their feelings to the way in which immigrants have been treated - not just in relation to the media's often prejudice but even in relation to the issues of refugee camps (which France have). They argue that this treatment is dehumanizing and wish to draw attention to the way in which immigrants are segregated and treated as 'other'.