It could also be that these magical rectangles aren't very resistant to exposure to water. They've gotten better over the years, but if someone loses their phone in the water, it's not long for this world in terms of function. And there's the fact that Aqua doesn't have prehensile limbs in his seal form. That certainly makes using a mobile phone more difficult.

Myca's smile brightens when his new friend isn't immediately put off communicating in this manner. He nods in answer to the question, then slowly types (since he's doing it one-handed since he still has food, too): Are you familiar with this device? I can teach you about it, if not.