LTR or RTL for a ‘Show More’ slider

I'm looking into re-designing product reviews on an ecomm website. My primary objective is to reduce the length of the page as right now it's kind of ridiculous.

My plan is to create a slider that shows extra content once swiped across which then hides the original content. Behaves the same the sliders on car websites when you pick between two different colours.

https://www.bmw.co.uk/vc/ncc/xhtml/start/startWithConfigUrl.faces?country=GB&market=GB&productType=1&brand=BM&locale=en_GB&name=e2r8b2c5#FABRIC

The question I have is, do I have the slider on the left or on the right? I.e. do I want people to swipe/slide left to show the extra information or swipe/slide right to left. This is for a LTR reading audience but I'm wondering if there one of these directions is more intuitive to a user who hasn't seen this type of function before.

Next option for me is to create a tool tip (or something along those lines) to explain how this function works but again, I'm trying to reduce the content on the page upon initial load.

RTL slider