Dropbox allows you to invite people to share your photo folder. You can either invite people to folders from 'Files' page or from the 'Sharing' page. You can create a Shared folder and share it with other people. To create a new shared folder, click 'New Shared Folder' button located at the top of the page. You will see 'Options' link to invite more people to an existing shared folder. If people accepts your invitation, then the shared folder will appear in the person's Dropbox account.