Transparent background durning upload

During upload, it is impossible to see if an image has a transparent background; instead, there is a white background, and pictures may be tagged incorrectly. Is it possible to add a patterned background for images with a transparent background? Also, it would be great for the magnifier feature, so there is no need to open the image in a new tab to see details up close.

Custom themes found on about:custom css style will usually expose transparent backgrounds. I myself have one on that makes tagging them a cinch.

Alternatively, if you prefer the default white, there is a custom CSS you can use there that installs the typical checkerboard pattern on images with transparent backgrounds here too. Take your pick, as custom CSS is super easy to implement (Go into advanced settings and scroll down to "Custom CSS style" and add the code here into it).

Thanks, found it
/* Show a checkerboard pattern behind transparent images */
#image {
--checkerboard: repeating-conic-gradient(transparent 0% 25%, #77789244 0% 50%) 0 0 / 32px 32px;
background: var(--checkerboard);
}
/* Show a darker/lighter checkerboard behind the image on hover, depending on light/dark theme.
* (It would be nice to use :active instead but that conflicts with the note toggle)
*/
html #image:hover, body[data-current-user-theme="light"] #image:hover {
background: var(--checkerboard), var(--grey-9);
}
body[data-current-user-theme="dark"] #image:hover {
background: var(--checkerboard), var(--white);
}
@media (prefers-color-scheme: dark) {
#image:hover {
background: var(--checkerboard), var(--white);
}
}