How about this?

Is the image purely decorative/e.g. if the picture never loaded does the audience miss out on some piece of information? If not then empty alt text suffices (this is less applicable to social media posts)

Otherwise imagine you have this picture and you’re telling somebody on the phone about it.

You’re not going to go into a full description of every element

“a small child on the left side of the picture is picking up a maple leaf with their index and thumb and handing it to the person on their right” who is a 50-60 year old woman with dirty strawberry hair and wearing horn rimmed glasses”

That’s too much and doesn’t “convey” the photo.

And you wouldn’t say “kid hands something to another person” since that’s not enough.

Let’s say you have an article about the fall and all the fun activities families can partake in. What matters is that it’s a young kid showing their grandma a leaf.

So something like this “Young child and grandmother at City Park. He is handing her a newly fallen leaf”

Or, if it’s an article about children nature education programs then it may say

“Teacher and a student in the park. The student is presenting a maple leaf to the teacher”

If it’s a post about your kid it may say

“Timmy showing his grandma a leaf he found while playing at City Park”