The shop welcomes you if the sales staff makes a 3 second assessment of you and concludes that you are well off and a probable customer.
If you are a regular customer who have made many expensive purchases from the shop recently, then you are especially welcome.
If the shop sales staff assesses that you are a no-hoper with no buying power, they not only won't allow you to play around with new camera models or new lenses --- they won't even welcome you. They will just ignore you.
Don't blame them. It is human nature. It is a commercial enterprise.