Reminder that "national boundaries with mercator projection" maps are, while on the surface interesting, on a meaningful enough level are less useful due to sheer degree of variance. Small (sized) countries get buried to thr point of not being visible, while large (populated) countries get over-generalised to the point of meaninglessness.
Presumably that's why the flags are so popular as well, I doubt Belgians are sending Belgian flags to one another in the DM's. Or maybe they do, I wouldn't know.
Volume. They only use heart emojis in morse code to communicate all their messages in NI. Also the entire government website and all companies start and end their webpage with a mandatory 600-heart header/footer, for security.
a worked example: if england/scotland/wales all use heart ❤️ 49% and use tears of joy 😂 at 51%, and then northern ireland was to use heart ❤️at 100%, you can imagine this would tip the whole uk over
even more freaky, you could make all 4 constituent countries use heart ❤️ at 49%, make each constituent use a different unique emoji 👍😀🥰😼 at 51% each, and then the aggregate would show that heart ❤️ is still the most used across the UK
now consider for each place on this map, they are ranking more than just 2 emojis. the map itself says that tears of joy 😂 is only scoring 5% worldwide, and that's 1st place. with margins of 5% and under to be deemed winner, it's no wonder funky effects show up