(Side note: as a physics teacher, Odo's constant violation of the Law of Conservation of Mass has always bugged me)
In their great trilogy, Millennium, Judith and Garfield Reeves–Stevens propose that Odo shunts some of his mass into/from subspace as he changes form. A bit of a handwave, yeah, but it has the benefit of making sense in-universe.
Chimera (****½)
Chimera is a great episode that explores a great deal of what has gone unsaid on DS9 so far. The most unsettling truth is that the Founders are kinda right, the humanoid races are a bit racist towards them, and their ability to take any form does cause suspicion to be cast towards them. At the same time, Changelings like Laas are smug pricks. They view themselves as higher lifeforms and look down on us as limited beings that are destructive and dangerous. In time, Laas's disturbed form of Changeling pride would lead humanoids to hate his kind, and Laas would set out to kill them in his belief that he's protecting himself. Laas allows us to see the beginning of the Dominion without actually seeing it. Near the end, we get a vision of how it all started.
For Odo, this is an eye-opening experience. He has always been aware that he's treated as an outsider, Laas just forces him to contemplate it. He has become so accustomed to fitting in with humanoids that he doesn't realise all that he's missing by not shape-shifting all the time. His friends like and trust him, but maybe that's because Odo only relates with them in a humanoid shape. How would the likes of O'Brien or Worf react if Odo decided to have a conversation with them in the shape of a luminescent octopus, or a ball of flame? They may not be opposed to Odo acting in such a way, but it would make them feel weird and understandably uncomfortable, so Odo chooses not to do these things.
It's interesting, I think the episode does indeed say this, but I think it also presents a strong case for Laas being unreasonable in his conclusions and the Starfleeters (somewhat less so the Klingons) behaving appropriately.
In any social situation, one must suppress their individuality to some degree or another. Without that, no one would every listen to anyone else, no one would ever comply with simple requests, society would grind to a halt.
So the question becomes one of degree: how much individual expression does a society permit? Even the most free societies put some limits on individual expression (fire in a crowded theater, etc).
Then there's the issue of cross-cultural interaction. No one likes Loud American Tourists. When you're a visitor in another culture (which Laas certainly was), you have to be respectful, to the extent you are able, of that society's laws and customs. Laas does not do this, and, in fact, goes out of his way to be rude.
Laas proclaims his dislike/mistrust for/of monoforms loudly. What is his justification? Enough monoforms treated him badly over a long enough period that he has concluded that all monoforms are bad. And then he gets ticked at O'Brien, for expressing his dislike for/mistrust of changelings, even though O'Brien's justification is virtually identical to Laas's. (And is somewhat more convincing, since there is much more variety among monoforms than among changelings.) While I'm sympathetic to both views, and at the same time do not fully agree with either, Laas doesn't have a leg to stand on. He's being a hypocrite.
The episode reminds me of this hypothetical situation: a white (American) man starts going to a church which is comprised totally of African-Americans, and which worships in a traditional Black Protestant style. Thing is, he's rather insensitive to the traditions, behaves rather arrogantly and selfishly, and is just generally pretty unlikable. Some members approach him after service, a few Sundays later, and inform him politely but firmly that his behavior needs to change if he wants to continue worshipping there. The man overreacts and accuses them of hating him because he's white.
Umm, no. They don't like you because you're being, as GodBen says, a prick. That's the biggest reason.
It's the same thing with Laas. He intentionally provokes ill-will from the station residents and then acts all wounded when they don't like him.
Yeah, the Starfleeters could have been better. But Laas should be expected to meet them half-way. And he doesn't.
This is where my love of counting things comes in handy, because we can actually chart Odo's decline as a shape-shifter through the seasons.
Season 1: 6
Season 2: 6
Season 3: 3
Season 4: 13
Season 5: 3
Season 6: 2
Season 7 (so far): 1
As you can see, other than the random spike in shape-shifting in season 4 (which is inflated due to Odo taking part in Changeling drills), Odo's shape-shifting has been declining throughout the seasons. He has only changed shape on screen once this season, and that was a joke about his umpire outfit. (Also note that one of the shape-shifting occurrences in season 6 was when he "wore" a tux, and two of the occurrences in season 5 were jokes about his sexual anatomy and the appearance of Old Odo in Children of Time.) Odo doesn't shape-shift much publicly any more. The real reason for this probably has something to do with shape-shifting being Odo's gimmick back in the early seasons and as he developed as a character the writers didn't need to rely on it any more, but Laas' claims do make a compelling case in-universe.
I never thought of this before, but I really like it! I am sure it was not intentional on the parts of the writers (I think you're right in that his character developed away from the gimmicks, and that Worf'sParmach is right in that it was a budget thing too), but it sure makes a great connection!
