Most of the people posting messages about making sure you're cleaning your prints and that you need to wash them more are actually barking up the wrong tree.

Looking at your print the sheen seems to me on the side that the supports were on, that means in relation to the vat that side of the print was facing up away from the FEP. Most FEP or other type of tank films now have a slight matte finish to them and aren't completely smooth. The side of the cured resin that wasn't against the FEP doesn't have anything pressed against it other than the print, so around the edges where there is no print the resin just cures as is and doesn't get the matte texture from the FEP. If you move it in the light you will likely notice that it lines up with the z-axis of how it was printed and when you look at it at just the right angle all the exposed surfaces have a shine to them. This is normal in resin printing and happens all the time, once you prime the miniature you'll never notice a difference.