What makes Camelia uncomfortable at work?

That afternoon, at work, Camelia discovers she's alone and is happy to be able to work in peace. Spencer suddenly appears, having been downstairs doing work. He gets closer to Camelia, telling her to keep working and experimenting. It unnerves Camelia, but then Matt arrives, holding two cups of coffee. Spencer says hello, talks with them for a little while, and heads back downstairs.