Just my two cents from my PIQA of the last PR.

• in the image block, the browse button isn't aligned to the right with the dashed rectangle surrounding the image that's above it
• the embed block and image block dashed areas don't have the same width
• the focused text field of the embed block isn't aligned with the top dashed area (which makes sense if you analyse it: then you see they're the same width - but I personally don't like that)
• there isn't enough space between the video option checkboxes and the above asset chooser field
• the Preload focused area isn't the same height as the gray arrow gray square to its right
• the Close, Save, Save & Publish buttons have a font size that's too small. It's supposed to be the same as in other places on the system, yet if you open an asset chooser you'll see there's a difference.
• in the video block, the check boxes and radio buttons aren't aligned with the field captions (Type, Asset, Alternate image, etc.)