The beaded slip that runs around the opening is not part of the main frame. It is a separate piece, and it is the last thing to go on.
Our artisans make it that way on purpose. The outer frame is carved, pierced and gilded as one job. The plate is then bedded into the rebate from the front, and only afterwards is the beaded slip fitted around it and fixed - not glued into place, but held by small brass fixings that can be released.
The consequence matters in a house. Should the plate ever need to be changed - after a move, or a knock, or simply because a later owner wants a bevel where there was none - the slip comes off, the glass lifts out, and the pierced carving and its gilding are never touched. On a frame where every leaf is cut through and hand-gilded, that is the difference between a small job and an unhappy one.
The slip also serves the eye. It gives the leafwork a hard edge to stop against, so the carving stays lively without spilling into the reflection.