Looks like the answer is (at least for this older system), come in from both sides of the tyre with two separate arms, and have each of those arms have their own little wheels on, so as you move inwards it lifts up the tyre and just rolls your mini wheels a little bit. Clever.
The system in London Gatwick UK is done by Stanley Robotics from France (which was acquired by HL Robotics from South Korea in 2024), but it could be similar.