If you add items via one of the options in the Import menu, they will appear at once.
If you're using the e-mail option and you're using the US server (if your Wardrobe URL starts with us2.carlyletheassolutions.com), make sure you send the e-mail to that server (wardrobe@us2.carlyletheassolutions.com). Otherwise it will go through the German server and will take way longer to arrive.