Oh I see it now. Sorry it looked at first that the girders were all level with each other, which wouldn't have matched with the profile of the road, but yes it does look like another 1-2 lanes could be added. I think they had previously said it would have 1 additional lane than the current setup. Again, that only makes sense if they repurpose the bus lanes to a regular traffic lane, still not clear whether that will happen or if they will retain them for emergency use or circulation.
Looking at the cars for scale, it looks like there's enough space for two more traffic lanes, the two tracks and centre platform. I suspect they may build the additional traffic lanes first (possibly just for construction access initially, not for general use), quickly followed by the rail/platform deck by September.
It certainly doesn't look like there is any more room , although a recent reply from the Stage 2 team to me suggested there would be an additional lane once things were completed. Trying to find that response for more clarity.