What determines theme compatibility

view full story

http://forum.xda-developers.com – Beyond ROM specific themes (stock, CMx, AOSP, etc.) what problems are most likely from flashing a theme that is not specific for S3 -- that is, I can't tell if it's specific for S3. Other than screen resolution issues I'm guessing maybe missing icons? The only threads on theme compatibility I could find mentioned having a backup, just in case theme didn't work (would ZipThemer backup be sufficient?) and possible endless reboot (and how would I get out of that?). Only making sure ROM and theme matched seemed important. (HowTos)