There are a lot of layers to this one: In Weezer's video for "Take On Me", the blend of hand-drawn animation and real-life footage is straight out of the 1985 video for a-ha's original version of the song.
The band miming the song in Weezer's version is not Weezer, but Calpurnia, the group led by Vancouver actor Finn Wolfhard, of Stranger Things fame. Calpurnia is playing neither itself nor Weezer, however, but Avant Garde—one of Weezer frontman Rivers Cuomo's first bands from the '80s. Wolfhard, of course, plays the young Cuomo, complete with teased hair and hesher-friendly denim vest.
Check it out:
Wolfhard is no, um, stranger to playing a younger version of a guy in a band. In fact, that's how the actor-singer-guitarist met Calpurnia drummer Malcolm Craig, as Mike Usinger reported when he profiled the band in December:
Calpurnia started with Wolfhard jamming with Craig after the two met on the set of a video for Toronto agitators Pup—where they played younger versions of the band’s members.
Here's that Pup video, which came out in 2016: