I already feel disrespected if a colleague makes me feel like sending it. If a friend tells me to get him a beer from the fridge because they're too lazy to get up, 7/10 times I'm going to do it. They're not going to be insulted when I don't because they know that they don't deserve anything, and they'll probably more often than not get up if I asked them the same thing.
If somebody at work tells me to do something for him that would take the same amount of time to do themselves, we're literally in a context where time is money and they're telling me that my time is worth less than theirs. It literally better be (some people are higher up than you, or currently managing a larger thing than you are), or else it's an insult, and I mean to be insulting them back. I'm actually saying that I think that they're either lazy or stupid, or spacing out and need to wake up.
edit: there's a parallel in Spanish forms of address where the way you ask friends to do something is to just announce that it's currently being done, and the way you formally ask someone to do something (like a work colleague) is to use a hypothetical (the subjunctive) basically saying "this is something that could be done." It's important not to presume the right to spend a colleague's (or superior's) time.