The lighting in this season is different, more moody, more dreamy, compared to the more realistic cold and bright hospital lighting of the later seasons. The cold open is long—we see the patient running late, we get a reference to a boyfriend that isn't at all related to anything about her illness or diagnosis, we get to see her friend, her dealing with students. The show is, I think, trying to get us to care for her before we see her fall ill, make us have a personal stake in this. As the cold opens get shorter (and have bait and switches), the show's purpose changes to making us interested in the patient, not necessarily care about them or who they are beyond a puzzle for House.

The dialogue is a touch clunky—"I'm just the lowly infectious disease guy"—but it gets its job done, and the show does get better about it very quickly. It is also interesting to see what the pilot reveals about the characters. It's the very first episode, it has the duty to establish a lot of important characters.

Right off the bat, before we even see House, we're informed that he has a cane by his own voiceover, implying that regardless of what everyone else sees, House's perception of himself is very much centred around the cane. We're also told, both in his conversation with Wilson and later Cuddy, that House is a slacker, House does not care for treating patients, but he does enjoy solving interesting cases. We're also shown his pills, though it is not implied (yet) that he has an issue.

Wilson lies very early into the episode, and cut exposition from the script implies that this is not a one-off thing. House has treated many of Wilson's "cousins" before. This immediately shows two things: House and Wilson are not friends in the typical sense (the script says you'd be hard pressed to call them friendly), and also even though House apparently takes patients based entirely on how interesting they are, the fact that the patient is Wilson's cousin does affect whether he takes the case or not. The script also has a scene where Wilson grabs House's cane to stop him, implying that Wilson (despite House's claim) does not really treat House differently due to his leg.

One of Cameron's first lines is explaining House's methodology to Foreman, showing Foreman as the new guy and Cameron as someone who wants to help him out. Cameron also lies to the patient, further establishing her as someone who cares for patients, takes a personal investment in cases, and is the only one of the fellows who believes in House's diagnosis. She also later defends House to Foreman, something she'll continue doing throughout the seasons despite literally never being rewarded for it. The pilot also sets up her character arc and hints at her backstory—her damage, so to speak—in her conversation with House.

Foreman is very clearly set up to be the main character from the fellows. The show starts with him as the newest fellow. He disagrees with House in the ddx, but very quickly comes around and suggests a corollary to House's motto, pleasing House immediately. The script calls him Grasshopper, and it is implied that the mentor-mentee relationship he has with House is supposed to be very important. Foreman gets the first one-on-one scene with House, where he (as the audience stand-in) is the only one who gets an explanation for House's cynical perspective of the world, and he's surprised House by not immediately folding and doing whatever House wants.

Chase is. there. He is very much a non-entity, the only one of the og3 to not get a one-on-one with House in the Pilot, the only one House didn't pick himself. He is implied to only have gotten the job because of a call his father made. The script mentions that Chase's brilliant idea apparently came from a book his father wrote. We get a smidge of personality—Chase maintains neutrality, or apathy, if we're being less generous. The patient almost dies because Chase thought she fell asleep. He doesn't believe in House's diagnosis, but he doesn't fight it like Foreman does. He thinks Cameron shouldn't have given the patient false hope, but he also didn't do anything to stop her in the patient's room. Even when he gets an idea, he prefaces it with disclaimers.

Cuddy is so much more involved in this case than she is in other cases House takes on as the show goes on. She's set up to be an… antagonist of sorts, provide friction to House's madness, someone to be the straight man and stop him from treatments with no proof. Also establishing that they do have somewhat of a relationship beyond just employer/employee, with Cuddy apparently researching the reference House makes to fire back at him later, and her being entirely unphased by House yelling at her, both of them separately trying to bring the elevator quicker to get away from each other, and Cuddy apparently letting House not do clinic duty for years, only bringing it up when he's finally showing some interest in actually doing his job again.

And the Pilot ends with House finally talking to the patient. The conversation is very revealing about House in two ways: one, that he does actually care, and that's why he stays away from patients, not because he's apathetic—he dislikes caring, he dislikes opening up. And two, House is a cynic. He doesn't think there's a difference between dying on a hospital table due to another misdiagnosis and dying in your home at peace, he doesn't understand why the patient is choosing to do this at all. Which is probably why this conversation does not work in getting Adler to agree to the treatment.