I can\'t figure out for the life of my to select from a collection with the or parameter. It\'s not working at all for me and I can\'t really find any documentation
or
The $or operator lets you use boolean or in a query. You give $or an array of expressions, any of which can satisfy the query.
You provided only one element in the array. Use:
find(array('$or' => array( array("brand" => "anti-clothes"), array("allSizes" => "small") )));