During the nineteenth-century all-seeing eyes were a common Mormon image. They seem to have been borrowed from Masonry and represented the presence of God. Accordingly, the symbol was frequently associated with temples, and appears in numerous places on the interior and exterior of the Salt Lake Temple. This image, however, is much earlier and comes from the St. George Tabranacle.
In addition to the all-seeing eye, notice the image of the clasped hands. There are a number of meanings that could be associated with this. For example, it could refer to the friendship of the Saints or the friendship between man and God. This was also a symbol frequently associated with the temple or the afterlife and appears frequently on nineteenth-century Mormon tombstones. The crowns could refer to the promise that the faithful may become kings and priests, queens and priestesses to God. The “Holiness to the Lord” motto is associated with temples, and appeared on lots of Mormon images in the nineteenth century. The motto “Faith and Union,” as far as I know, is unique to the St. George Tabranacle.
This image is several feet tall in real life and is painted on the wall behind the pulpit in the main meeting hall of the tabranacle. Interestingly, at one point in time it was painted over by the tabranacle maintance crew. The image was restored on the orders of Elder Boyd K. Packard.