When viewing the index page of the code snippet library, I usually find the title of the snippet the most useful description of what it does. However, the title is not emphasised, so it's not always easy to locate it.
By increasing the size of the font for the snippet title, it would decrease the amount of time spent searching (looking) for the title which is a good thing.
After the change, some titles would likely need multiple lines that didn't before, but there are some that already need the multiple lines and Mozilla at least doesn't expand the box for them.