Head-mountable device with connectable accessories

A system comprising:

• a head-mountable device comprising:
• a frame;
• a processor;
• an optical module within the frame;
• multiple arms extending from the frame;
• and
• multiple HMD connectors each disposed at a corresponding one of the arms and comprising:
• a respective HMD positioning element;
• and
• a respective HMD communication interface;
• and
• an accessory device comprising:
• multiple end portions at opposing ends of the accessory device;
• and
• multiple accessory connectors each disposed at a corresponding one of the end portions and comprising:
• a respective accessory positioning element configured to mechanically and releasably engage the respective HMD positioning element;
• and
• a respective accessory communication interface configured to communicate with the head-mountable device via the respective HMD communication interface,
• wherein the accessory device is configured to be arranged in:
• a first configuration with each of the accessory connectors engaged to a corresponding one of the HMD connectors to provide operable communication between the arms of the head-mountable device;
• and
• a second configuration with a first one of the accessory connectors engaged to a first one of the HMD connectors and a second one of the accessory connectors engaged to an external connector of an external device to provide operable communication between the head-mountable device and the external device.