We've seen how we can use commas to indicate circumstances.
Now, let's look at how we can use commas to add smaller details.
For example, the comma in this snippet helps add details to a thing (the narrator's favourite toy):
One time I went out back with my favorite toy, a plastic Tinkerbell figurine.
This snippet is effective because it raises a tiny question—what is their favourite toy?—before answering it with a little extra detail.
After maths I went outside to eat my favourite lunch, a meatball sub.
Before I could play games I had to do the worst thing of all, my English homework.
To make up for it I bought Moses something he really wanted, a set of bassy headphones.
