You can share individual images by clicking on the menu in the thumbnail view and selecting "Share record". You see the icons when you move the mouse over the image.
A new window opens and you get a link you can share.
In the same window, you see the icons of various social media channels at the bottom left (red circle). You can embed the image there directly.
The DOI (Digital Object Identifier) is best suited for referencing individual images, if available. It is usually found in the information view.
Important: Not all catalogues have DOIs.
You can share entire categories the same way you share individual records. However, only with a link and not in social media.
As a logged-in user, you can also share collections. Please read the following Wiki entries: