Part of the purpose of the card icon at the top left is to make the card type stand out when you have them fanned out in your hand. Since Lost Souls never stay in your hand it makes sense that they chose not to use an icon at the games inception.
It's a old school thing having cards without icons. Lost Souls are the only real "resource" we have in Redemption. Most old school games from the time period did not have icons on their resources.
MTG lands are laid out very similar to our lost souls and Pokemon energy tokens are both good examples of games from the time period that have a similar layout to our lost souls.
For other players that weren't around, remember we only had one special ability lost soul until Womens and we were still forced to use no special ability lost souls until Angel Wars when the game finally had enough lost souls that players could make decks with only special ability souls. The game had no need for a icon back in the day.
If anything I think Lost Souls should have even more art to them and no icons. Something akin to what MTG is doing with their full art lands. I'm not sure how this could be accomplished... since everyone uses Special Ability souls which have oodles of text... but it would definitely add even more visual flare to Redemption!
