What to look for
Start with neutral gray, then try several solid colors. Look for outlines that remain fixed while the background changes. Broad tints and brightness differences are worth recording too, although they can have causes other than burn-in. Compare the same area at a comfortable, consistent brightness.
Temporary and persistent marks
Temporary image retention and permanent panel wear are different problems. These browser patterns cannot distinguish temporary retention from permanent wear. Follow the display maker's rest and maintenance instructions, then repeat your observations under the same conditions. Avoid running unusually bright static patterns for extended periods.
What the moving patterns do
Color changes, moving bars and a reversing checkerboard help you inspect residual shapes against different backgrounds. They are observation patterns, not a repair procedure. If the mark remains visible in ordinary viewing, keep photographs and contact the device maker rather than relying on repeated color cycling.