I feel like there's a logistical reason for the dessert variance, because we see it in other places as well, but when we see it there's a consistency to those exceptions. Like the JFK-MEX-JFK flights seem to generally use the small bread plates for pre-plated desserts both ways, but YVR flights I've been on have all had the standard 1300+ mile catering on inbound YVR flights, serve plated desserts in the same dessert bowls outbound that the ice cream/cheese is served in inbound... And the desserts I've had outbound out of YVR cost at least twice as much as the ice cream and cheese, so I'm not sure there's much of a financial motive, if any. If those exceptions wobbled a little I'd get it, but it happens with such consistency that it almost seems to be the specs for the local caterer require changes on certain inbounds and not others, on top of what's delivered on the outbound from that local caterer.