The only way I think it would be detectable is if someone is watching you very closely, such as if you are a necro on a raid stacking like 15 DoT's without ever sitting. But the chances of someone watching you like that in such a specific situation are basically 0.
I've used it every single game since I started using MQ2 and never once had an issue with it. It's really great with new toons who have a low meditation skill.