Sharing makes it possible to post the album on social sites. The post will include the Album's title (or the current folder's title), the description and the theme image - where it's possible.
Note, in order many Facebook functions to work you have to create an App on their Developer site →. This is possible only if you have a "Page" but not for personal accounts.
Social sites got a bad rap this days - and with a reason. As they are built on a free business model they're trying to monetize on your private life. I feel concerned too. Only my Google account has gathered some 5 GB of data on my private life, and while it's unlikely a human would read it through, AI's can dig out various information for whoever pays for it - and that's truly frightening.
Tiger skin has a possibility for visitors to opt-out such services, see Tracking consent and cookie policy settings →
Naturally, Google Analytics is the one that collects the most data on users, but this is known and this is the sole purpose of this tool.
Tiger is a dynamic skin (or web application), which means the slide images are loaded on user interaction by the underlying javascript. This makes it possible to have smooth transitions between images, slideshow, continuous background music and many functions only possible in a dynamic page, for instance search. However, many social sites can only share the base index.html page, but not the internal stage of the page, e.g. when you view an image in large size. This is partly due to security reasons, because an internal stage can be easily manipulated. Facebook called this as "Share customization", and they stopped this in 2017 pointing fingers on the manipulation of the American Elections. So, in the Lightbox only the "Share links" will work, but none of the buttons and not even the Facebook share.