Let's start with the names.

There are
Small Blue Potion and
Lesser Blue Potion. The
Lesser one was uploaded with the
1st update, it's also pictured in the image you attached to your reply.
So, you're talking about the
Small one for sure. If it's not working for you, you probably didn't import its icon to your map or you've imported it incorrectly. Please check the icon
import path.
I didn't forget to upload
Blue Potion's (sphere shaped one), coz it is Warcraft 3 default icon, but it is hidden in the World Editor. Just paste "
ReplaceableTextures\CommandButtons\BTNPotionBlue.blp" to the icon name section n your Object Editor.