The dropbox automate synching photos of your ISO or OS devices but it’s only saved the photo files on the filing system and not directly to iPhoto. Hence you will need to do an extra steps to import photos to the iPhoto.
Here are what you do:
1) After logging into DropBox, open iPhoto.
2) Top selection of iPhoto, select “File”, in file drop down, select “Import to Library” wait a second. It will open the import window.
3) Locate ” DropBox ”
4) Select the DropBox file you saved and would like to import.
Steps are super simple and this seems the only way can import photos by folder and not individually. Give a go.