My browser / operating system: Windows NT 10.0, Chrome 133.0.0.0, No Flash version detected

https://scratch-mit-edu.ezproxyberklee.flo.org/projects/611327484/ there are multiple sprits that appear as a grey box with black question mark.

server issues, reload multiple times or use turbowarp

Related question. Is these grey question mark boxes only apply to when it is trying to load SVG images? or can this block appear even if the said image is a bitmap file? I feel like it would only appear on svg related images, but I guess it could end up appearing for bitmaps too.