Popularity = A condition of being liked, admired, or supported by people.
It has nothing to do with the population in-game. Though a high population may make getting a higher popularity more difficult.
Use the last tab(Overveiw) to find your rating and click the magnifying glass (lower right under the word 'Requests') to find out which ratings(yellowed) is holding you up. Science/Culture is the usual suspect for high population city; pay rate too low, taxes too high, finances, food levels low...
Other tabs (Science/Culture) usually have the magnifying glass pop-up icon that can help in judging what needs your attention.
Right Click Odysseus' Hero Hall to find the complete list of his requirements. Ensure you have them ready as well.
PS: you image isnt assessible as its a login requirement to view
[This message has been edited by user3 (edited 07-12-2018 @ 07:01 PM).]