Two different things share this shape in these lines. One is the literary call to someone, as in drink, my dear sister, and the address to a brother, which sounds solemn and is usually deployed for comic weight. The other, and the more common one online, is writing the polite ending 요 as 여 to sound soft and playful, which is what the greeting spelled oddly, the catchphrase, and the question about crying only on high-rating shows are all doing.
Register: the call is literary; the 요 respelling is cute and internet-casual