Wwhat are screamers subliminal messages?

A screamer is usually a surprising image that appears on the screen for a very short amount of time, often accompanied by a startling sound.

For example, you might be watching a calm nature video, when all of a sudden a picture of a skull appears and a screaming sound plays for a very brief amount of time. Then, the video either resumes or ends completely.

Another example might be an image that you are invited to look at for a long time, when suddenly the image changes to something obscene or frightening before quickly changing back.

The word "screamer" can describe either the whole video or animated image, or just the surprising part itself.

Usually screamers are pretty easily detected, and I would not describe them as subliminal messages.

However, sometimes people who create screamers claim that a picture contains subliminal messages that the viewer should try to find, in order to get them to look at the picture for a long time.

EDIT::

There is a specific screamer referred to as Subliminal Messages spread by Albino Blacksheep. This is supposedly one of the more frightening screamers. (Encyclopedia Dramatica)