Yes, the image in today's tweet from DHS is fascist propaganda, very similar to fascist propaganda from Nazi Germany in the 1930s.
And when you share it unmodified ... you're amplifying fascist propaganda. Why are you doing that?
It's easy not to share fascist propaganda -- just don't share the image. Or, if you think it's important for people to see it, then take the time to deface it first -- a big red X over it, or "FASCIST PROPAGANDA" in big red letters to get the point across.