By you know exactly which friend
Hey, BFF! Thank you SO much for your thoughtful birthday post on Facebook.
Honestly, I am moved by the pure simplicity of "HAPPY BIRTHDAY!" Your employment of capital letters and that exclamation point captured your enthusiasm with a level of nuance that definitely could not have been achieved with more words. Huge props for not using any emojis at all. They would have distracted from the whole two words you wrote.