Shawn Mendes circumvented traditional routes to a recording contract by posting short clips of himself singing other people's songs on the video-sharing service Vine.

These were no more than a few seconds -- Vine's restrictions set the limit at six seconds, which is hardly enough time to cover a chorus -- but it was enough to set some teenage hearts aflutter, which led to a contract with Island, which led to an EP in 2014, which led to the full-length debut Handwritten in 2015.

That was a two-year march to an album, which should've been enough time for Mendes to learn how to engage a listener for at least 60 seconds, but Handwritten is pretty thin gruel.

Some of this is down to material, songs that feel like a laboratory-generated fusion of Jason Mraz's singsong loverman schtick and Ryan Tedder's icy adult contemporary.

Although he has songwriting credits on two-thirds of Handwritten, he can't be blamed for the rinky-dink tunes: his producers could've sharpened the hooks so they all stuck like those on "Stitches" and "Kid in Love." What he can be blamed for is the fact that he can't hold the audience's attention for any longer than on Vine, relying on his puppy-dog eyes and croon to get him through a song.

Cute he may be, but he has charisma that lasts no longer than a GIF, as Handwritten makes painfully clear.