a bit large
When something is like a cat that's been told it's the king of the castle. It's not huge but it's definitely not tiny and it's getting a little too comfortable with its own size.
This shirt is a bit large. It looks like it was worn by someone who just won a bet and now has to wear it forever.
That kid's backpack is a bit large. It's like it's trying to hide a small army inside.
This cake is a bit large. It's like it's saying, 'I'm not done yet.'