1st time Work colleague,Hi Pets,
You, my name is Petra,
2 time work colleague Hi Pets, how is going or how are you Pets,?
You, look glance around like you looking at someone else,
and just say i thought you were talking 👄 to someone else working here,
You, It's P-et-r- a extra eemphasis on how you pronounce say your name correctly,
like a school teacher or a tutor teaching elocution classes,
3 or 4 times
Work colleague Hi Pets,
You 🙄 eye 👁 roll glance stare body language
Or and say
Its P-e-tr-a emphasis on repeat on correct way of saying your name
It could be in your work place calling each other shortened versions of names can be just a sign of affection they like you find you ok,
obviously it can be over familiarity too,
(the tone way they say it etc)
it doesn't mean allways like one poster on here,
said that it's way of trivialising and belittering you,
I agree with you, that it's straightforward to just say full name the way you prefer