April Fool's 2018 joke for RiiConnect24 (a fake Discord client for Wii). It loads a rickroll video.
The player.swf (ew! Flash) file can be used on the Wii Internet Channel in order to play videos in .flv format, since the Wii unfortunately lacks an HTML5 video player. It was taken from the Wii Channel interview pages from Nintendo's Japanese website site.
Here's a template for the embed code:
<div id="swfcontent">
<object type="application/x-shockwave-flash" data="player.swf" width="384" height="256" id="flvplayer" style="visibility: visible;">
<param name="id" value="flvplayer">
<param name="wmode" value="transparent">
<param name="allowFullScreen" value="false">
<param name="allowScriptAccess" value="sameDomain">
<param name="quality" value="high">
<param name="flashvars" value="filename=http://link.to/flv/file/here">
</object>
</div>```