When creating and sending a Playlink, the assets will be watermarked based on the folders settings by default. If you wish to apply a different watermark specifically for a single Playlink, you can do so in one of two ways.
The first way is to create a watermark template with the elements of the watermark you wish to add to the Playlink, and then select that template to apply it. For more on creating a Watmermark Template, please review our help doc here: Watermark Templates
Once you do so, when creating the Playlink, you'll have the option to use the default watermark, or you can select the watermark template that you created:
The second way to create a Playlink-specific watermark is to do so "on the fly." In order to do that, select the 3 vertical dots next to the watermark preview, and click "Create Override."
You'll then have the ability to create a new watermark using the same interface as above. Once done, click Save, and the watermark will update to this newly created watermark.
Note: it will be given a default name, but that can be changed by clicking the pencil icon, updating the name, and clicking Save.