A repeating leaf that runs up a long side has a trap in it: repeat it faithfully and it starts to look stamped out.
So our artisans break the repeat deliberately. Each successive leaf in the run is curled a little differently from the one below - one turning its tip outward, the next rolling it back, the next opening flat - and the cycle is set to an odd count so it never lines up with the leaf directly opposite on the other side of the plate. The two sides answer each other without being copies.
The run is also stopped differently at each end. At the bottom the leaves turn into the base scroll; at the top they release into the crest. Neither end simply cuts off mid-pattern, which is what makes a climbing design look like it grew there rather than like a length of moulding that ran out.
None of this is visible as technique. It shows up only as the impression that the frame is alive, which is exactly the point.