Asking for rows 4,6 etc is treating the table as if it was an array.
But most databases state firmly that the order of results is undefined (could vary) if no explicit sort order is applied.
If the table has a field holding the name of the icon, you can use the database and SQL as it is intended to be used.
Select * from myIcons where iconname in ('BigButton','Sunshine','Apple','Frogx3');
and it does not matter what index /row number they live at.