"not a whole lot of people around here use these types of emojis"? I don't get your point, I doing something less people do.. So what?
Read "idiosyncrasy", "writing quirk", or "writing style", that should give you a good idea of the point being discussed here.
What a big cellphone! 🤣 😊 😱
All the things above aside, I have to say you go to a length to prove that you wrote from a PC. I think people will normally just take a screenshot of their screen, a snipping tool perhaps, showing the taskbar or anything that hint to a desktop mode. You did... what? Wrote a draft, take a picture of it with your phone, send the image to your PC and upload them to talkimg? Or did you uploading the image to talkimg from phone, sending the link through email or draft feature [I'll admit I've use this "cloud service" numerous times when I have to work on a post from several devices] and copied the image to your draft on PC?