gistfile1.cs

public class Movie
{
  public int Id { get; set; }
  public string Title { get; set; }
  public ICollection<Actor> Actors { get;set; }
}

public class MovieModel
{
   public string Title { get; set; }
   public string[] Actors { get; set; }
}

public class MovieToModelMapping : Profile
{
  Mapper.CreateMap<Movie, MoviePresentationModel>()
    .ForMember(m => m.Actors, x => x.MapFrom(y => y.Actors.Select(a => a.Name)));
}