Here is a Terracotta floor that has been finished in a Topical sealer.
The reason a topical sealer was used in this case was due to the floor bearing a faily low amount of traffic and the sheen will remain for a long while.
Downsides of a topical sealer include:
The sheen wears off after a while
In some cases the sealer can peel from the tile if the tiles where sealed with oil and wax in the past
Future cleaning to the floor will require a lot of work to fully remove the old sealer again before it is re-sealed
Here is a short video explaining the differences in finishes available for a terracotta or clay tile floor
