Tohkatz, I put in pictures pretty much how I always did but I usually have an extra step because I'm using an old school camera and not a smart phone, so my first step is to go to this site to reduce the file size of the photos:
https://www.reduceimages.com/
I do that first and download them to my computer through that site. It doesn't do much, but it reduces my pictures and doesn't set off my virus scanners.
Then I start out typing in the Quick Reply box. When done, I click on Go Advanced, and find the Manage Attachments button in the middle of stuff, it doesn't stick out -- look for it! It's a quick click to go into Downloads.
Once you are in the attach file screen though, it defaults to the old vertical layout. The actual button you need is way to the far right, I have to stretch my window to find it.