When it was my turn, I was assisted by that same teller. She told me that she liked my eye glasses. Normally, I'd feel 100% complimented. But since I heard the teller compliment the previous customer in the same way, my compliment felt discounted, or commoditized.
Was I being too sensitive, or was it the teller being too generous with compliments?
If you're going to compliment a lot of customers, say it in a way that won't be overheard by other customers. Each customer deserves to feel the full value of a compliment.