So, let's start over.
Three examples, one with minutes (you make it clear to the reader how many), one with years (you make it clear to the reader how many), and one with millennia or eons (you make it clear to the reader how many).
Use your sequential art toolbox in different ways for each of the three.
And there's a bonus to anybody who can avoid repeating specific techniques used by others, and I'll arbitrate whether a caption with numbers and a caption with words spelled out are different enough, but I'll start by saying they aren't.
So, a caption noting the passage of time is out, thanks to Harry who claimed that tool.
But there are other ways a caption can be used, so let's see what you come up with.
And if you just can't come with an object other than Roberts's gravestone, then use the gravestone.
The point is for you to be really comfortable with using this sequential art tool, and my assessment right now is that nobody here is comfortable with this.
So, let's see what you've got.