one) The first time Cobb hires Eames, he thinks Eames must not trust Arthur since he spends so much time watching him when he thinks no one's paying attention. These days Cobb hardly even notices the way Eames' eyes track Arthur the moment they're in the same vicinity. The three of them haven't worked together in quite a while, so it's hardly a surprise when Eames' eyes snap to Arthur the first time he walks into the room. However, what catches Cobb's attention is the look of relief that washes across Eames' usually bland expression when he does.
two) Anyone who's spent very much time with Eames knows he observes everyone constantly. It's why he's so good at what he does, after all. Yet, Yusuf has never seen him watch anybody with quite the intensity as he does Arthur. It's not until Yusuf catches Eames' actually peeking at Arthur for the third time in less than fifteen minutes that he realises Eames' indifference is a cover for something much different.
three) Saito's entire focus has been on his goal and the necessary steps to arrive at it. He's certainly aware of every detail about each of the individuals working for him, but he hasn't stopped to worry about their idiosyncrasies. Now that they're all about to board the plane, he takes a moment to observe Eames' complete inability to take his eyes off of Arthur and wonders if Eames has any idea about the blatant signal he's sending.
four) Ariadne has always been impressed with how much the tension increases when both Eames and Arthur are in the same room. She can understand why so many people think they hate each other, but she's pretty sure it's something else. The quick glance Ariadne see Eames throw Arthur's way just before they descend to the third level — a confused mix of concern, trust and longing — seems to confirm her theory.
five) Robert Fischer is rather preoccupied with the odd dream he had during the flight, but as he collects his luggage, he can't help but notice the way one of the passengers he shared the first class cabin with is staring at another. There's so many unspoken thoughts and feelings contained within his gaze, that Robert wants to walk over and tell a complete stranger that he needs to go talk to the other man. The second man looks over and meets the first's eyes. His lips quirk into the hint of a smile, a ghost of a dimple transforming his whole face. He tips his head in silent invitation, and the first man joins the second, the two of them heading out into the bright L.A. sunshine together.