In review, why are some question summaries different than others

Question

Some summaries are large, many are small, some are in orange.

I'm going to slap my head when I get the answer, I just know it.

Answer 1

Large with circles are Questions.
Small with squares are Answers.
Orange = no answers
Green = Accepted answer, or has an accepted answer.

Also if the title is orange it means you already clicked on that link.