Maybe it's because I am a native english speaker but your reply is offensive and embarrassing to native English speakers around the world. You can do better, America. You just have to try.
The conservatives make pledges to solve social issues, like homelessness, all the time. They almost never actually follow through. Instead they often act to make the problem "go away", often to the detriment of those they claimed to want to help.
One of those pledges was to cut homelessness in half. However no extra money or resources were actually provided to do this. This sign is a protest of that (and many other) lies. At a glance, it's one of their normal lies. It's only when you read it more carefully your brain goes "wait, what?!?".
The sign was made by someone else and stuck on top of an existing ad on the tube (the name given to the train system in London).
Occasionally people manage to stick these on, and have them go unnoticed for a good while (or it takes a while for someone to get to removing them).
Somewhat recently, someone made an ad for an illegal weed shop on the clearnet, and had those on the tube in a similar fashion for a good while before they were removed.