So do you want that the portfolio page has all thumbnails for every gallery, or just some random thumbnail from each and then link to the specific gallery document?
In your portfolio page, under each section use a maxigallery call that queries 3 random thumbnails from a specific gallery for example:
Logos
[!MaxiGallery? &gal_query_ids=`9` &order_by=`random` &limit=`3` &manage_target=`9` &embedtype=`slimbox` &pics_per_row=`3`!]
Graphics
[!MaxiGallery? &gal_query_ids=`10` &order_by=`random` &limit=`3` &manage_target=`10` &embedtype=`slimbox` &pics_per_row=`3`!]
T-Shirts
[!MaxiGallery? &gal_query_ids=`11` &order_by=`random` &limit=`3` &manage_target=`11` &embedtype=`slimbox` &pics_per_row=`3`!]
Events
[!MaxiGallery? &gal_query_ids=`12` &order_by=`random` &limit=`3` &manage_target=`12` &embedtype=`slimbox` &pics_per_row=`3`!]
And create links below those thumbnails for users to access the gallery documents (with <a href="[~9~]".... etc).
Then in each of your gallery page, use:
[!MaxiGallery? &display=`embedded` &embedtype=`slimbox` &pics_per_row=`3` &max_thumb_size=`110` &max_pic_size=`0` &thumb_use_dropshadow=`1` &is_target=`1`!]
But I’m not exactly sure what you’re after.. so.. does this sound right?