Presidents signing stuff into law is almost always a publicity stunt (politics), once passed it becomes law in 10 days regardless if the president signed it. The exception is if it passed during the last 10 days of a session; president has to sign for it to become law so congress can know before they leave Washington. The pocket veto being a veto of inaction, president does not sign or veto a bill that was passed in the last 10 days of the session and just forgets about it in his pocket or wherever.
Many sources including government sources like to pretend that the president must sign a bill into law but it is not the case. Most of how the "news" reports on this stuff is purely political and has no connection to reality.
