A Question For the Phone and Social Media Individuals

I've received messages on social media and on my phone from people who has these little boxes with some kind of scribble or design within the inside of the box or square. I'm sorry but I am not that savvy when it comes to these sort of things but I would like to know if anyone knows what I'm referring to and what does this mean? For instance, today...someone sent me a thank you message and at the closing of the message it read thank you JS and then there were these squares/boxes right after my initials. Thanks in advance to those who responds to this...I really appreciate it...JS.

 

Well...its not just on the phone...you see ....the other day I got a thank you message on Facebook and the guy had those little squares/boxes behind my name. It was like three or four of them and some others had done the same thing before too. I did assume that these squares meant something of an affectionate nature because there was a guy who had a huge crush on me earlier this year and he had those boxes after his message to me as well.