I think there is a reason for your girlfriend's behavior.
First, it may be that you just broke up and are not used to it. For example, you once had a toy that you loved very much, but one day, the toy was lost, broken or thrown away. You always felt awkward for a while, but it doesn't matter. This is human nature. When this time has passed and I am in a good mood, I won't engage in some boring activities, similar to changing the WeChat avatar and screen name.
Second, because she just broke up, she wanted to say goodbye to the past. You are changing the WeChat avatar and screen name, which is actually an external manifestation of the change of concept. That is to say, she wants to bid farewell to the past completely, so that everything before can be replaced, change her mood, change her life, and changing her screen name and screen name is just one of the manifestations. This is why a song sings: I have a new haircut and my phone number has changed.
Third, after she broke up with you, she may still be single and have more time to take care of herself. She doesn't have to spend more time on you, don't think about what you want to eat, don't think about what clothes you like her to wear and what makeup she wears. She has a lot of time to kill. If she is not satisfied with her WeChat avatar and screen name, then change it. It can be said that she tried to get it back from you.
Fourth, after breaking up with you, it shows that your relationship has come to an end, and she is preparing for attracting the opposite sex. At this time, she hopes to attract the attention of other opposite sex, start the next love, and change her WeChat avatar and screen name, which actually reflects that she will adjust herself to the best state and prepare for new feelings. Changing the WeChat avatar and screen name will be more perfect and better attract the attention of the opposite sex.
Therefore, no matter from which point of view, frequently updating your avatar and screen name actually represents farewell to the past and preparation for a new life. Now that we have broken up, don't put too much energy on him. It's not that a good horse can't go back to grass, but the problems that existed when you broke up may not have been eliminated because you realized the importance of your last relationship. Instead of on and off, you torture each other, or you are alone. What is lost is lost. What other functions can excessive addiction have besides hurting people and hurting themselves?