RenderInline::generateCulledLineBoxRects() disregards the height of inline boxes (such as images). Instead, it always uses the font metrics's line height for the line.
int logicalTop = rootBox.logicalTop() + (rootBox.lineStyle().font().fontMetrics().ascent() - containerStyle.font().fontMetrics().ascent()); int logicalHeight = containerStyle.font().fontMetrics().height();
Created attachment 242863 [details] Test
Turns out this is correct behavior.