A recurring requisition about Oxygen Builder repeaters is how to how alternate layouts. This is a relatively simple thing to do with some basic CSS.
How and why does this work?
Assuming you are using columns to layout your contents in a side by side manner (like above), they are using flexbox. Flexbox has a nice property called flex-direction:row-reverse, which does exactly what it sounds like... It reverses your row order.
With the repeater, apply a custom class to the div within. Then, use the code above to specify that every even child (that's what 2n means) as the row reverse applied to it. You can specify different child elements (ie 3n, 4n) to spice it up.