Here's a comparison of the Romulan emblems seen on the Warbird back wall in #StarTrekTNG's "Data's Day"⬆️ and "The Mind's Eye"⬇️. As can be seen, they are slightly different (the border of the bottom triangle, for example). Learn more at Ex Astris Scientia:
https://www.ex-astris-scientia.org/inconsistencies/romulan_emblem.htm