There are a few settings on the account level that affect all new uploads. They are modified on the Settings → Upload → Defaults section.

General Settings

You can set the default moderation and category under General Settings section. Note, when you set the moderation to Approved, all new videos will automatically appear in the Video site if your account has it configured.

Poster Image

Each new upload can receive a default poster, which can be then changed in the media appearance page for individual videos. Alternatively, each new upload will have a poster image which is the most representative frame from a video.

The account default Poster image will be used as default when creating new live events.
Poster image is displayed as a placeholder for video, before user clicks on the Play button.

Note, the maximum poster image size is 10 MB.

Watermark

Please check a separate article for watermark to configure it on the account level.