It pains me to see how he repeats the same action for each subtitle-block element, doing the same thing 3 times total. Imagine you had a scrollable area with 20

It pains me to see how he repeats the same action for each subtitle-block element, doing the same thing 3 times total. Imagine you had a scrollable area with 20 blocks. If it's a mockup editor, then it should be easy to customize from JS to make anything useful from the mockup. If it's a site builder, better add support for templates, so that one would then be able to drag and drop data (e.g. json) onto the canvas and bind it to a template to automatically populate a whole set of elements at once. P.S. No matter how slick your UI is, if it's not programmable, it's not useful.