I thinks they're o.k.
Several rules mentioned above are rather elastic (you can stretch them like a rubber band), things like no advertising between pictures... Usually means people don't like a large block of advertising between images, but if from whatever position you look at the page you clearly see the next row/block of thumbnails BELOW the advertising then it seems to be o.k. with most... I tend to put text between images, but I hardly ever link it, since surfers seem to scroll to the end anyhow (or close the gallery on first sight).
The other day I came across a site not permitting 'animated GIFs' and still listing my gallery; I keep my GIFs usually rather simple, not too "loud", and with slow transitions (so they're less annoying).
http://www.picxs.com/webmast.html - and let me know that you're from ggandj... (I don't list all GimmePink galleries anymore - too many)