It's the same black blob. As usual, there's no higher-resolution data for small remote islands.
Though if it weren't labeled as "Sandy Island", I would think it's just an artifact of some kind. It certainly doesn't look like any real island at that distance.
Its seems to exist as an incorrect shoreline in the freely available NOAA GSHHS Shorelines data[1] which digitalglobe[2] uses to crop low-resolution satellite images to be replaced with high-resolution land area imagery, with nothing available for the location this results in the black spot.
Landsat[3] never showed anything there, especially at this size.
Earliest depiction[4] I found in the short time via oldmapsonline.org dates back to 1881
While this otherwise well explored map[5] of 1862 does show nothing in place.
GeoGarage[6] pretty much says the same.
This only shows how slowly low priority public datasets are updated/maintained since the french maritime authorities SHOM don't have anything in their official charts of the area.
Though if it weren't labeled as "Sandy Island", I would think it's just an artifact of some kind. It certainly doesn't look like any real island at that distance.
http://goo.gl/maps/NUWhA