You can of course completely skip the picdrop.com address for sharing your galleries and use your own internet address instead. This way you can share a link in your emails, WhatsApp chats, Instagram DMs etc. that perfectly matches your branding.
With picdrop’s Web Forwarder, picdrop remains invisible when you share your gallery links. For example, www.picdrop.com/johndoe/gallery becomes johndoe.de/clients/gallery
If you are already registered with picdrop, you can find the installation files here and the instructions for installing the Web Forwarder here.