Como extrair detalhes da instrução select para um método diferente e ainda manter o carregamento antecipado?

No entityframework, posso carregar explicitamente as propriedades ao adicioná-las ao método select, assim:

var workhours = dbContext.WorkHours
    .Select(w => new WorkHourLookupDto()
        {
            Id = w.Id,
            StartTime = w.StartTime,
            EndTime = w.EndTime,
            RecreationInMinutes = w.RecreationInMinutes,
            TotalWorkHoursInMinutes = w.TotalWorkHoursInMinutes,
            Customer = new CustomerMiniDto
            {
                Id = w.Customer.Id,
                Name = w.Customer.Name
            },
            Description = w.Description
        })
    .ToList();

var workhours2 = dbContext.WorkHours
    .Select(w => _factory.CreateLookUpDto(w))
    .ToList();

Agora o workhours cria a seguinte consulta de seleção:

exec sp_executesql N'SELECT [w].[Id], [w].[StartTime], [w].[EndTime], [w].[RecreationInMinutes], [w].[CompanyId], [w].[Created], [w].[CreatedBy], [w].[CustomerId], [w].[Description], [w].[LastModified], [w].[LastModifiedBy], [w].[UserId], [t].[Id], [t].[Name]
FROM [WorkHours] AS [w]
INNER JOIN (
    SELECT [c].[Id], [c].[Name]
    FROM [Customers] AS [c]
    WHERE [c].[CompanyId] = @__ef_filter__CompanyId_2
) AS [t] ON [w].[CustomerId] = [t].[Id]
WHERE ([w].[CompanyId] = @__ef_filter__CompanyId_0) AND ([w].[UserId] = @__ef_filter__p_1)',N'@__ef_filter__CompanyId_2 nvarchar(4000),@__ef_filter__CompanyId_0 nvarchar(4000),@__ef_filter__p_1 uniqueidentifier',@__ef_filter__CompanyId_2=N'3AD04E77-9654-4BBB-A8E8-4DE1335A7516',@__ef_filter__CompanyId_0=N'3AD04E77-9654-4BBB-A8E8-4DE1335A7516',@__ef_filter__p_1='8220F8B8-720D-42E8-9357-2256470EA206'

E workhours2 cria a consulta:

exec sp_executesql N'SELECT [w].[Id], [w].[CompanyId], [w].[Created], [w].[CreatedBy], [w].[CustomerId], [w].[Description], [w].[EndTime], [w].[LastModified], [w].[LastModifiedBy], [w].[RecreationInMinutes], [w].[StartTime], [w].[UserId]
FROM [WorkHours] AS [w]
WHERE ([w].[CompanyId] = @__ef_filter__CompanyId_0) AND ([w].[UserId] = @__ef_filter__p_1)',N'@__ef_filter__CompanyId_0 nvarchar(4000),@__ef_filter__p_1 uniqueidentifier',@__ef_filter__CompanyId_0=N'3AD04E77-9654-4BBB-A8E8-4DE1335A7516',@__ef_filter__p_1='8220F8B8-720D-42E8-9357-2256470EA206'

A fábrica é assim:

public WorkHourLookupDto CreateLookUpDto(WorkHour workHour)
{
    return new()
    {
        Id = workHour.Id,
        StartTime = workHour.StartTime,
        EndTime = workHour.EndTime,
        RecreationInMinutes = workHour.RecreationInMinutes,
        TotalWorkHoursInMinutes = workHour.TotalWorkHoursInMinutes,
        Customer = _customerFactory.CreateMiniDto(workHour.Customer),
        Description = workHour.Description
    };
}

public CustomerMiniDto CreateMiniDto(Customer customer)
{
    if(customer != null)
        return new()
        {
            Id = customer.Id,
            Name = customer.Name
        };

    return new();
}

Por que a consulta difere ao extraí-la para uma classe diferente, portanto, método?