The image used for promo displayed several different aspects of Indian culture and the Hindu religion. However the image was considered insulting to Indian religious sentiments since it was insulting to one of the most revered deities in India, Lord Shiva. Some people also complained about the cultural appropriation visible so clearly in this case.
The picture was originally the cover photo for the event on facebook but it has now been removed and only the title of the event is the visible. Warehouse project also ultimately released an official statement where they apologized for any offence they might have caused.