ZTE Concord II profile pic?

[AC Question]

Hi. I'm going to try and explain this as best I can. It's a minor issue but one that proves very irritating.
I have a ZTE Concord II. Almost at any time, you can swipe down and a drop down menu will appear. There is an option you can press in the upper right hand corner of this drop down menu which will display several different options. These options appear in the shape of squares and include brightness, settings, wi-fi, data, auto rotate, battery charge, airplane mode, bluetooth, and location. Just before the brightness option, in the upper left hand corner, there is a picture with a name. The picture and name represent whomever owns the phone, or at least that's what I've deducted.
My issue is that I have set the picture and I cannot seem to find a way to change it. Clicking the photo doesn't do any good, as it doesn't display any options. I've tried going to Gallery and setting a different picture from there, but it doesn't give me that option.
I'd really love to change that photo, as it's quite embarrassing. I'm at a loss.
Help would be very much appreciated.