Complex sentence: The heatagram was first predominantly featured on the cover of HIM's 2003 album "Love Metal", which was designed by Valo and Janne Uotila, and has since then been featured on numerous albums, singles and videos by the band.
Split into simpler sentences: The heatagram was first predominantly featured on the cover of HIM's 2003 album "Love Metal", which was designed by Valo and Janne Uotila. The heartagram has since then been featured on numerous albums, singles and videos by the band.