What I noticed
The logo was not merely a cleaner white. On my MacBook display it appeared to produce more light than LinkedIn’s own white cards. When the logo entered the viewport, the surrounding page seemed to recede. When it left, the page looked normal again.
Here is what was actually happening. The JPEG’s visible RGB values had not been redrawn; its embedded color profile told the browser to interpret them as Rec.2020 with a PQ transfer curve. Under PQ, values near white describe HDR light levels rather than ordinary SDR white. Once the browser handed that image to macOS, the logo and the surrounding page were no longer being rendered in the same brightness range.
Apple calls the gap between SDR white and the display’s brightest available white EDR headroom. LinkedIn’s interface remained at SDR reference white while the Ghost logo could be mapped above it. There was no dark overlay on the website: macOS could reserve part of the display’s range for the HDR highlight, and my eyes judged the unchanged page white against a much brighter neighbor, making the page appear to recede.
The screenshot took a different path. Saving or viewing it as an ordinary SDR image tone-mapped the mixed scene into a smaller range, compressing the Ghost’s “super-white” back toward normal white. The trick only survives when the site preserves the profile, the browser renders HDR still images, the display reports usable headroom, and the operating system allows it.
LinkedIn and Instagram take different files
HDR is not one universal file format. Pick a destination to see what it needs: HDR Pop creates the LinkedIn-style PQ JPEG, Instagram expects Ultra HDR, and screenshots usually flatten both into SDR.
LinkedIn: Use the PQ JPEG from HDR Pop. This route is the most likely to survive a custom LinkedIn image upload.
How the extra headroom feels
These are two real files: an ordinary JPEG and the same Ghost image tagged with a Rec.2020/PQ profile. Move the slider to blend between them. On a compatible HDR display, the 100% end can produce light beyond page white; on SDR they may look the same.
Why this works as marketing
It creates visual priority before the message is read. That makes a simple logo unusually effective, but I would keep it to one small highlight. Essential information should remain readable in SDR, and the real file needs to be tested on the real platform because sites can strip the metadata at any time.