Nixon watches are an interplanetary company responsible for mass producing and supplying watches to many civilians of the Human colonies. Their watches apear to be similar to Citizen's Eco Drive series. The watches differ in the fact that there is some form of background logo seen in Advertisments in game.
There is a real watch company named Nixon Watches, it is possible the company paid to be advertized by Guerilla Games. The symbols in game are identical to the acutal brand logo