It would probably be described as non-standard. It's just an informal, quick way of asking a question, by writing a statement but putting a question mark at the end. I don't recommend that learners use it though. Even when used correctly, you might find it being corrected by teachers/native speakers who think that you've done it accidentally.
The reason I added a wink was because I actually thought that my questions might be taken as a little abrupt, as if I were impatiently checking with you that you had finally grasped my answers. That isn't how I intended them to be read so, to indicate that, I added a smiley. The wink wasn't particularly relevant, I just wanted a smiley.
- For Teachers