It is new in your tank.
Magnifica have uniform color column. If your column is not uniform in color, it is likely not a Magnifica. Are there any verrucae on the column? Magnifica Verrucae are not very prominent, sometime we cannot see it, only slightly darker spots on the column. Are there any bands on the tentacle? I seem to see a few bands on the tentacles in your picture. Better quality picture will help.
If there are bands on the tentacles, then the anemone is a H. malu. This anemone species (malu) will stay small, up to 6-8 inches, and stay on the sand.
Wait for the anemone settle in. Good clear picture under normal light of the anemone, and good close up picture of the tentacles,the column, and the mouth of the anemone will in determine ID of the anemone.