A Placeholder Gallery is meant to be used in situations where you want a client to have a Gallery link, but not have it available yet. For example, you could photograph a wedding and put up a Placeholder Gallery the next day to let viewers sign up to be notified when the images are ready.
A Placeholder Gallery makes the Gallery URL viewable, but it doesn't show any images to the clients that view the link. Instead, it will ask for an email address for visitors to sign up. Once the Gallery images are available for viewing, the people who signed up with their emails will be notified.
To use a Placeholder Gallery, you would toggle the "Placeholder" toggle on in the Gallery Settings. This makes the Gallery live, but not viewable. Once the Gallery is finished, you would upload the images to the Gallery, then turn the Placeholder toggle off to make it viewable.
We recommend you upload an initial image as it will show up as the background image on the Gallery when we prompt the viewer to enter their email address.