Can't implement Iterator design pattern after JsonConvert when trying to Deserialize json

I have the following Object that matches the pattern of a JSON object i get from one REST request I send:

public class MyObject
    {
        public List<string> columns { get; set; }
        public List<List<string>> rows { get; set; }
        public DisplayValue displayValue { get; set; }
        public string currency { get; set; }
        public object alert { get; set; }
    }

    public class DisplayValue
    {
        public Id DisplayId { get; set; }
    }

    public class Id
    {
        public List<string> IdToName { get; set; }
    }

this object match to the response I get and the next code is working with the upper implementation of MyObject (I'm using C#'s RestSharp):

        var response = client.Execute(request);
        result = JsonConvert.DeserializeObject<MyObject>(response.Content);

Now I would like to implement the Iterator design pattern on MyObject since MyObject.rows is the only field I actually use.

So I've changed MyObject class to the following

public class MyObject : IEnumerable<List<string>
    {
        public List<string> columns { get; set; }
        public List<List<string>> rows { get; set; }
        public DisplayValue displayValue { get; set; }
        public string currency { get; set; }
        public object alert { get; set; }
    }


        public IEnumerator<List<string>> GetEnumerator()
        {
            foreach (List<string> row in rows)
            {
                yield return row;
            }
        }

        IEnumerator IEnumerable.GetEnumerator()
        {
            return GetEnumerator();
        }
    }

    public class DisplayValue
    {
        public Id DisplayId { get; set; }
    }

    public class Id
    {
        public List<string> IdToName { get; set; }
    }

But when I try to JSONConvert I get the following exception:

Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'MyObject' because the type requires a JSON array (e.g. [1,2,3]) to deserialize correctly. To fix this error either change the JSON to a JSON array (e.g. [1,2,3]) or change the deserialized type so that it is a normal .NET type (e.g. not a primitive type like integer, not a collection type like an array or List) that can be deserialized from a JSON object. JsonObjectAttribute can also be added to the type to force it to deserialize from a JSON object.

Any idea to why is this happening?