An inventory item to be picked may be selected along with an inventory location (e.g., storage bin) storing a particular unit of the item among a units of heterogeneous items also stowed in the inventory location. One or more images of the inventory location may be obtained and analyzed to determine a position of the unit of the item. Instructions may be sent to direct a device to illuminate the determined position of the unit of the item, and pick instructions may be sent to the same or a different the device. A device may receive the position instructions from a control system, and illuminate the determined position of the unit of the item within the inventory location. The pick instructions may direct an agent or mobile storage bin to a particular location and direct the agent to pick the unit of the item from the illuminated position.