Some of the seats have RCA style connectors which allow you to share media. I *think* (but don't quote me) that some media can be watched by connecting your device via USB.
I did look into this a while ago but couldn't find a practical way of doing it - so just use my laptop.
Besides - unless you have a very small laptop - it's likely the screen on that is bigger than the one on the IFE. Certainly higher resolution than on the older birds.