designed with a certain amount of flexibility, rather than being completely rigid.
That means the side can move inward or outward depending on what is happening inside the container.
And that’s why the little circle can look different.
Sometimes it’s pushed inward.
Sometimes it’s pushed outward.
Sometimes it looks almost completely flat.
And sometimes it looks like someone is gently pushing it from the inside.
Suddenly, that weird little circle makes a lot more sense.
It isn’t there because somebody thought:
“Let’s put a random circle on the side.”
There
