Poor Summer; she's so typecast.

You erred in your capitalization. From http://xkcd.com/about/

How do I write "xkcd"? There's nothing in Strunk and White about this. For those of us pedantic enough to want a rule, here it is: The preferred form is "xkcd", all lower-case. In formal contexts where a lowercase word shouldn't start a sentence, "XKCD" is an okay alternative. "Xkcd" is frowned upon.

This site seems to automatically capitalize the first letter of the first word you submit.

Actually, most HN replies favor brevity. I like that.

HN ♥ brevity

But... How do we know that the original author would know who Summer Glau is?

You erred in your capitalization. From http://xkcd.com/about/

How do I write "xkcd"? There's nothing in Strunk and White about this.

For those of us pedantic enough to want a rule, here it is: The preferred form is "xkcd", all lower-case. In formal contexts where a lowercase word shouldn't start a sentence, "XKCD" is an okay alternative. "Xkcd" is frowned upon.