Thanks Timothy for your reply.
I've attached two new screen shots comparing the source raster (Landsat) with the mosaic dataset
Are the visible pixels from the source rasters or the mosaic dataset overviews?
Right click on the Image > Zoom to Raster resolution to see if the pixels display the same. If they display differently, then there is probably an issue with the overviews.
The first attachement is a screen shot of the Zoom to Raster. Left side is the source raster. Right side is the mosaic dataset
Also, could you please provide a screen shot showing the original imagery for this same view?
I've attached screen shot, but not same area as original post (second attachment). When zooming in, on the original raster we see the distinct pixels of the Landsat imagery (left), but blurry effect on the mosaic dataset view (right)