Judging by how their last gen product was laid out, it's on the underside of the board.
https://eshop.aaeon.com/pico-itx-boards-11th-gen-intel-pico-...
https://eshop.aaeon.com/pico-itx-boards-11th-gen-intel-pico-...
It is impressive they fit 2 RAM slots, 2 NVME slots, 2 Ethernet ports, an HDMI, DisplayPort, and 3 USB slots on that thing. Ridiculous in a way that I like :)