In my desktop web browsers (Edge, Firefox, Chrome), on the slide pages, I can see the image tile above the image . But when I view on iPhone or iPad, in both Firefox and Safari, the image title just isn't there.
I'm not sure if it's caused by some custom CSS or misconfiguration on my part, or if Gromit is designed that way.
It has nothing to do with iOS, or even with whether the device is a "mobile" - it's driven entirely by the window size. In a desktop browser, try shrinking the window, and you'll see the effect.
ETA: When I did this, I was thinking primarily of a title bar that would be showing the album or folder title, which is generally not all that important for the slide image. Losing the image-specific title is a little different. I'll consider changing the routine to move the text down, rather than hiding it. That's what the thumbnail page does. But that will reduce the space available for displaying the image, so....
I think I can probably have my cake, and eat it, too. With a little CSS trickery, the title can still be shown, but truncated if necessary. A punchy one- or two-word title would still be entirely visible. But never any wrapping, so no extra space being chewed up. Compare the two screenshots (from the Chrome device simulator).
It would take some extra tinkering to account for font size issues, but not very difficult. I'll keep it on the "maybe in the next release" list (the Mercury skin could use some of the same kind of fiddling).
In my beta skin version (yes, it was easier than I thought), there's a new Hide page title on small displays checkbox on the Layout > Slides panel. If checked, it does what the skin does now. If not checked, it shows as much of the title as it can without wrapping, using ellipses to indicate that there's more there. There's no option to let the title wrap and push everything else down, however.
To make the most of the available space, it also doesn't force-center the title between the navigation icons on a small display (depending upon the options you've chosen, there can be a lot more of them on one side than the other). See screenshots.