Interestingly, if I copy that first character in the table early enough in the page load, it's a hyphen. If I copy it later, it's an en dash. Considering that this article is from 2010, I assume there's some JS added in the last 12 or so years that's autoconverting it.

EDIT: Wayback confirms it's supposed to be a hyphen: https://web.archive.org/web/20120120121527/http://www.punctu...

It’s the server (probably WordPress’s fault), not JS. – is an en dash:

    $ curl -s https://www.punctuationmatters.com/en-dash-em-dash-hyphen/ | grep -A6 '<h3>What'
    <h3>What do they look like?</h3>
    <table style="height: 139px;" width="289">
    <tbody>
    <tr>
    <td><strong> &#8211;</strong></td>
    <td><strong> hyphen </strong></td>
    </tr>

I guess they respected their own recommendations: "when you're trying to illustrate what a hyphen looks like" was not one of the recommended uses of a hyphen!

I should also note that this whole point seems at best a point for typography geeks. These are three almost identical marks that have very similar uses. I am completely convinced that no one has ever disambiguated a phrase by noticing that something is a hyphen and not an en-dash or vice-versa.