Will icing sugar change the outer 'shell' of a pavlova?

Because you used icing sugar (super fine ground sugar) it made more of a crispy meringue than an pavlova. You need Caster Sugar - 1/4 cup per egg white, add 1 or 2 tablespoons at a time and beat each addition really well until the sugar is dissolved (check by rubbing a pinch of the mix between thumb and forefinger - there's no gritty feel). Add 1 tspn white vinegar and 1 tspn vanilla per 4 egg whites in the last minute of beating. Heap mix up on baking tray (make the diameter of the raw pav. the size of a bread and butter plate - it will spread).