Handling different client and server content - not showing initial render

In the hydrateRoot page, it is mentioned that
"This way the initial render pass will render the same content as the server, avoiding mismatches, but an additional pass will happen synchronously right after hydration."

which means that the initial render on the playground should show "Is Server", but it shows directly "Is Client" which is very confusing for learners and doesn't show the real behavior.
I tired opening the sandbox in external window, and it indeed shows "Is Server" first and then changing to "Is Client" as expected.

In the Website:

In The sandbox (using the fork button):

Comece pelo playground incorporado da página hydrateRoot e compare seu comportamento com o sandbox externo aberto pelo botão de fork. Reproduza o exemplo e rastreie como o playground lida com a hidratação e sua renderização inicial. O trabalho estará concluído quando o exemplo incorporado mostrar brevemente "Is Server" antes de mudar para "Is Client", correspondendo ao comportamento documentado.