Why do people like to say おめでとうございます under the photo in Instagram？
And how do you say " This is a good photo”？
→ →素敵なお写真をシェアしていただいてありがとうございます[emoji]これからもよろしくお願いいたします

これからもよろしくお願いいたします I think this sentence is only used in the end of meeting.
Are there any other situations that I can use this sentence?

Question

Why do people like to say おめでとうございます under the photo in Instagram？
And how do you say " This is a good photo”？
→ →素敵なお写真をシェアしていただいてありがとうございます[emoji]これからもよろしくお願いいたします

これからもよろしくお願いいたします I think this sentence is only used in the end of meeting.
Are there any other situations that I can use this sentence?

Answer

You are right!Japanese have some meaning about those sentence.

First,"I wish your (and our)company will have many more successful years."on business.

Second,"Let's keep in touch." and "I wish you and me to keep good relationships."

Second meaning is always used in personal communication. But you can also use on business.

These are my assessment.
Thank you.