If you are using the haircut as a 'timeline' thing and a representation of the character as written in seasons three and four and your interpetation of the character in those seasons, fine.
I hope you aren't saying that the haircut itself had anything to do with the way the writers saw the character in those seasons because that is patently ridiculous.
For me (beside thinking that Lois looked good in the shorter hairstyle) the haircut was a 'marker' of the change in the relationship between Lois and Clark/Superman. It's the start of the period where Lois and Clark are a true couple.
Many think that this change of the relationship was the 'downfall' of the series and that (like has happened to other series in the past) resolving the sexual tension led to its demise.
Tank (who thinks that most Hollywood writers have fun with sexual tension, most can't write a stable relationship to save their lives)
