Can this be achieved?

Hi,

I’m trying to find a way of changeing the tooltip appearance on thumbnail hovering in an album gallery overview.

On this competitors site they have a nice way of showing the image title.
This looks more professional than current tooltip in NGG.

Does anyone know how this can be achieved?
If so how and in which file. Or can it be done through css?

Thanks.
Rolph
My page

https://ww.wp.xz.cn/plugins/nextgen-gallery/