My site’s images move when you scroll. Does this meet accessibility standards?

From a conformance standpoint, the animation you describe conforms with WCAG 2.1 AA, but it would not conform with Success Criterion 2.3.3: Animation from Interactions, which is a AAA success criterion.

Animations or other additional movements that accompany scrolling have been known to cause motion sickness, headaches, or distractions for some users. Parallax scrolling, where background and foreground elements move at different speeds as the user scrolls, is a common example.

One method to address this is to use a CSS prefers-reduced-motion query to automatically provide a non-animated version of the page for users who have already set their device to reduce animations. Another strategy is to provide a control on the page so users have the choice to stop all animations.

For a deeper dive into accessibility and other types of dynamic web content, explore the Adaptive Content & Other Page Requirements course from Accessible Web Academy.