Welcome to the Roku Community and thanks for posting regarding your inquiry of accessing your Roku Smart Home Cameras through Guest Mode.
Please be aware that through the use of Guest Mode, viewers will not be able to access to the Roku Smart Home Cameras. The only way to access Roku Smart Home Cameras wold be to view through a Roku device that is linked to the same Roku account.
We hope this provides clarification and if you have any other inquiries in the future, please don't hesitate in posting again in the Roku Community.
Roku Community Moderator