orgmode plantuml 输出的图片文件背景是透明的，为什么在 orgmode 中显示的确是白色的背景？

[xshumeng]

#+begin_src plantuml :file images/example.svg
  @startuml
  !theme cerulean-outline
  skinparam backgroundColor transparent
  skinparam handwritten true
  title Example Sequence Diagram
  activate Client
  Client -> Server: Session Initiation
  note right: Client requests new session
  activate Server
  Client <-- Server: Authorization Request
  note left: Server requires authentication
  Client -> Server: Authorization Response
  note right: Client provides authentication details
  Server --> Client: Session Token
  note left: Session established
  deactivate Server
  Client -> Client: Saves token
  deactivate Client
  @enduml
#+end_src

但是在 plantuml 模式的预览却是透明的