Hello,
I agree, this is a confusing one; I get a good number of docks for swimming/fishing, and always accept them. They are certainly great places to socialize with others, possibly get some exercise, and maybe even explore the surrounding area.
While your photo isn’t the greatest, it isn’t bad. You provided the dock as the anchor point for the beach, which can work in place of a place marker sign. Really, a place marker is just something at the location that can mark it, a meeting point of sorts, and a dock can certainly be a place marker.
There are also birds in the main photo, so I wonder if that caused the rejection in the first place. While we don’t want animals to be the focal point of photos, that’s not the case here; the dock is the focal point.
@admins You may want to look at this one.