This might stem from an anxiety issue. Of course an assessment or professional would ultimately make a diagnosis.

But it sounds to me as though you might be seeking approval in your own behaviour. Modelling it after what yous see would suggest you question your own behaviour. I think to some degree this is normal. We all do it in some way or another; however, it is the extent to which you do this that your are right to question.

If it makes you feel better, I am constantly observing people and how they do things and on occasion have picked up and altered my own habits accordingly (how I walk, modes of some dress, and yes I even eat my burgers upside down). In my case I have the unhealthy thought that I am being observed myself.