Image retention is scary to see on your OLED TV but often easy to eliminate. Many modern OLED TVs subtly work their own magic when you're not watching in order to remove the problem, as RTINGS demonstrated in a video released Friday. However, TV vendors aren't all doing perfect jobs at implementing OLED screens' compensation cycles.
Temporary image retention differs from permanent image retention, aka burn-in, in that it points to a change in the panel's thin-film transistor (TFT) layer, rather than degradation of the OLED layer. Untreated permanent image retention doesn't lead to burn-in, a Sony spokesperson confirmed to me, but anyone looking at a screen suffering from image persistence will want to eradicate the sticky images, fast.
These temporary artifacts can be the result of heat affecting the amount of light emitted by the OLED pixels and can happen within minutes of usage. But letting the TV cool down by turning it off usually fixes this.