The game does a bad job at explaining how Loyalty works. Here are some additional notes:
- Governors require 5 turns to establish (other than Victor). However, this delay does not apply to the +8 Loyalty bonus, which happens immediately (I'm not sure if the value actually updates instantly or after you click "next turn"). That's why p0kiehl suggested you move a Governor there asap;
- Population is the strongest defense against loyalty pressure. The faster you grow your newly settled cities, the better it will fend off incoming pressure from foreign civs (hence why a granary is important, as it provides both housing and food);
Loyalty pressure from population is the most important thing to keep in mind. The maximum pressure from population is +/- 20. Distance also plays an important role. The further away your city is from your other cities, the less positive pressure it will receive. The closest it is to foreign cities, the stronger the penalty pressure from enemy cities it will suffer.
Although there's no graphical difference, there's offensive and defensive loyalty, so to speak. Most manners of accruing loyalty are defensive, in that, they increase loyalty in your city without that actually increasing the loyalty pressure over foreign cities. The +8 loyalty from Governors is defensive, for instance. So is the extra loyalty from positive amenities. It is "defensive" because the +8 from your Governor is not actually increasing negative loyalty pressure in nearby enemy cities.
Population pressure is both defensive and offensive, but capped at +/-20, as I explained above. Meaning that if your city has a +20 Loyalty from Population, that +20 is not only having a positive effect in your city, it is also having a positive effect in your nearby cities and a detrimental effect in nearby enemy cities.
Amani's "Emissary" ability is exclusively offensive. It will not provide you a loyalty bonus in your own cities, but it will apply a negative -2 in all enemy cities within 9 tiles. The negative pressure is cumulative with other Amanis with the Emissary promotion from other Civs (I think? It should be).
So if you see a -2 Loyalty in "Other Effects" in your city, it's probably from an enemy's Amani. Yeah, "Other effects" just sucks and the game will often leave you confused by not providing detailed information.