Yeah, you have to learn to see those things... but don't be hard on yourself. HTML was never meant for doing anything resembling print layouts, and yet we're expected to do it for a dozen different screen sizes, using one hack on top of another - tables, floats, flexbox, grid, absolute positioning...
When I got moved from doing print design to the early web, we'd literally design an entire website at one size in Photoshop and use slices to cut all the interactive/hover bits out and put it all in a table. Nothing about web/app design has gotten simpler since then. Compare with the absolute ease and freedom of working with a layout program like InDesign or Illustrator, targeting a known print size. It's easy for a nontechnical designer to look at a mockup and say what's wrong with it, but it's infinitely harder to know what levers to pull in the giant puzzle of CSS and HTML to attain all the details of the static design. And sometimes the static design is just a launch point. In a case like that, if I were in the graphic design / art direction role, I would provide a logical style sheet, basically a list of rules about alignment and sizing, because I wouldn't expect the coders to be able to visually extract my intent or what I considered important just from looking at a comp.
When I got moved from doing print design to the early web, we'd literally design an entire website at one size in Photoshop and use slices to cut all the interactive/hover bits out and put it all in a table. Nothing about web/app design has gotten simpler since then. Compare with the absolute ease and freedom of working with a layout program like InDesign or Illustrator, targeting a known print size. It's easy for a nontechnical designer to look at a mockup and say what's wrong with it, but it's infinitely harder to know what levers to pull in the giant puzzle of CSS and HTML to attain all the details of the static design. And sometimes the static design is just a launch point. In a case like that, if I were in the graphic design / art direction role, I would provide a logical style sheet, basically a list of rules about alignment and sizing, because I wouldn't expect the coders to be able to visually extract my intent or what I considered important just from looking at a comp.