Impossible? No, just unlikely.
The fairly long Dictionary Thesaurus ambigram displayed to the left at first glance doesn't quite seem possible.
As you can see from the preview, this typographical marvel says 'Dictionary' one way and says 'Thesaurus' the other way.
If you wish to see the design inverted, simply move your mouse cursor over the graphic.
All items in the FlipScript store are already displaying the Dictionary Thesaurus ambigram. To see them, use the menu bar at the top to navigate to an item and the Dictionary Thesaurus ambigram will appear on everything you see.