Why can't you have iced coffee in front of a customer? I am not primarily customer facing but do a lot of integration and onboarding work in the field and have brought way weirder things to customer sites. Like a whole gallon of tea, and a six pack to put in their fridge for later.

Nobody - and I cannot stress this enough - fucking cares. Unless the job is some fake corporate butt sniffing gig where none of the people involved actually do any real work.