What is the fine-grained topic of the following text: During the annual Hong Kong trade fair, Elephone disclosed that it is working on a new flagship device which will feature a QuadHD (2560 x 1440) display, 4GB of RAM and a 20.7-megapixel camera with Sony’s IMX230 sensor. Only return the topic.
Elephone's new flagship device announcement at the annual Hong Kong trade fair.