Can be used for building portfolio or just simply showcasing your photos for personal consumption. Having MyCatalogue can also help you organize your photos that is comparable to an image organizer.
MyCatalogue has no link to DropMock and definitely without any watermark. The URL that will be used will be your own URL so you can claim 100% that the images are entirely your own.
Simple and very easy to use, in fact it can be done in less than a minute. Simply go to your MyDrive, pick the photos you want, click the eye icon, copy the embed code and then paste on to your WordPress site.