Her crime? Wearing a cross to work. Their claim: No visible jewelry. Her claim: Religious discrimination. Why? Muslims and Sikhs can wear visible signs of their faith, such as the veil, the turban, and the Sikh bangle.
Arguably, those religions are obligated to wear such adornment (although the veil is debateable in Islam), while crosses are optional in Christianity. Still, her argument has some merit. A turban is okay but a necklace isn't?
Britain has had issues with this kind of issue lately, and the natives seem to be getting fed up with policies that favor Islam and other religions over Christianity.