What determines the layers as seen in this photo of the dover cliffs in England: https://www.bing.com/images/search?view=detailv2&iss=VSI&form=ENAIMG&q=imgurl:https%3A%2F%2Fwww.bing.com%2Fth%3Fid%3DABTAD5FCAED6BB252274903455B414994DFB39A6A43186EE8DFC14C0A20A7F6A8D4%26qlt%3D90%26pid%3DInlineBlock&ptitle=©%20Nomad%20/%20eStock%20Photo&ajaxhist=0&selectedindex=1&id=2B518D6AB28750A9615C7EC4C39B1CE98C4C6519&mediaurl=http%3A%2F%2Fcdn.desktopwallpapers4.me%2Fwallpapers%2Fnature%2F1920x1200%2F4%2F40221-high-rocky-shore-at-the-ocean-1920x1200-nature-wallpaper.jpg&exph=1200&expw=1920&vt=0&ccid=SC%2BB3S%2B%2B&simid=608029559351019591&thid=OIP.SC-B3S–0-wg_cyVDGpbLwHaEo&pivotparams=imgurl%3Dhttps%253A%252F%252Fwww.bing.com%252Fth%253Fid%253DABTAD5FCAED6BB252274903455B414994DFB39A6A43186EE8DFC14C0A20A7F6A8D4%2526amp%253Bqlt%253D90%2526amp%253Bpid%253DInlineBlock&eim=1,2,6…Specifically, the thickness of the layers, and the color variations. The aforementioned link is merely one example, there are innumerous variations worldwide.
Firstly - those are the Cliffs of Moher in Ireland, not the (famously, White) Cliffs of Dover in England.
The biggest colour variations are caused by differing rock types - lighter sandstones, darker shales. As to why the thicknesses vary, there are lots of reasons - different depositional environments, different depositional climates, different erosion rates - no one reason.
Moher’s generally considered a delta-type sequence, so there’s a lot going on there, from river sandstones to turbidites at the delta edge.The middle part of the cliffs are Tullig Formation cyclothem - read more about that here. This citegoes into a lot of detail about that part of the stratigraphy of the cliffs, from page 187 onwards.
