No it uses miller columns above a data grid. If there are no Miller columns it’s not a Query Picker it would just be a data grid and that’s not what it’s for.
You need to adjust the columncount. You have it set to 1 but you have two columns. I will look into using one column as I can see the use of that but it’s not what Miller columns are for.
... to answer your other question, no a column is a column from a table not a grid. So you cannot have multiple columns as one column.