Another one of those language problems, lol.

Anyone tell me what this is.... would it be powdered egg white or is there something else in it?

There is egg white in it, several other ingredients as well. We use it mostly for making royal icing and flood icing.

Okay then its not what I thought it was.....

Does ordinary Royal Icing do well on cookies?

We thin it out and "flood" the cookie. It smooths itself out. This article explains how to dohttp://www.cakecentral.com/article54-How-To-Bake--Decorate-Cookies.html this:

I pulled this off of Sugarcraft.com regarding using powdered egg whites instead of meringue powder which also contains a hardening agent, salt, and sugar. We do not use regular eggwhites anymore for producing Royal Icing because of salmonella risks. I would think that you should be able to use pasterurized egg whites with some success.
Quote From Sugarcraft Site
Egg Whites, Pure Dried (egg albumen) - in wide demand by famous pie makers! with directions. Use in place of meringue powder, no additives here. NOTE: Don't expect the icing to keep as long as with using meringue powder. Use same equivalents. For liquid egg whites: use 1 tablespoon Dried Egg Whites to 3-1/2 tablespoon water. Two tablespoon of mixture equals one egg white. Use for icings, marshmallow toppings, chiffon pies, and angel food cakes.

Squirrelly, I just realized that Sparklycakes is in Ireland....I just bought a couple of British made cookie books and the royal icing recipes call for raw egg whites or 'pasteurized egg white product'. I don't think there is as much concern about Salmonella as there is overseas as there is in North America. Whenever I travel to Italy I still get shocked when I go to the grocery and the eggs are out on a shelf! Even in summer!

Hi Sparklycake,

In the UK meringue powder is sold under the brand name meri-white. It may be the same in Ireland