Describing a specific button in a specific corner is hard. Now you can just point at it. Turn on the element selector in the builder, click any element in your app preview, and it becomes a chip in your prompt, so "make this bigger" or "change this color" lands on exactly the thing you meant.
The chips are real: hover one and Emra outlines the element it points to right in the preview, they survive copy and paste, and they work in the mobile chat sheet. You can stack up to thirty picks in a single message when a change touches more than one spot.