It seems to work great on all browsers on my desktop but not so well on my smartphone, it opens off-center on my phone. Not that mobile support is a deal breaker for me but I thought I'd mention it.
Yeah I'm not sure if the screen dimensions are the same for mobile browsers so the way the current version of ReIMG determines that might not be compatible. Thanks for pointing it out. I'll keep it in mind for the 3.1 rewrite.