Found this thread whilst googling the same problem. Love the phone overall - and most of the sense customisations - but the gallery app is extremely poorly designed. For a start, I see no way to set it up such that I see my own flickr/picasa pictures. If I click on "my photos", it just shows photos stored locally on the phone. "Friends" allows me to select from flickr or facebook friends, but not google+ friends (google+ and picasa are integrated these days, in theory, although that's a whole other story).
I don't mind the option to browse recent posts friends have made either to facebook or flickr, but I'd prefer that to be buried under some top level heading i can just ignore, rather than spammed into the main gallery opening page. I mean, as it stands, even if you click on "friends" it doesn't show you a newsfeed of the newest pictures posted by friends on the chosen services. Instead, you have to browse and select a particular friend. This seems an entirely useless feature and feels poorly thought through.
I'm a (part time) professional photographer, and often use the gallery app on my N7 to show potential clients portfolio images that i've uploaded to picasa in "visible with the link" galleries. This is a really useful feature for me, and I'd love to be able to leverage the great display of the One for the same purpose. Instead, I'm having to use 3rd party flickr/500px/picasa apps, which is no great hardship, but not as neat.
Oh and one quick point of clarification: the true "stock" gallery app in AOSP features no integration with any online photo services. It just shows pictures stored locally, presumably in a predefined "pictures" folder. The N7 gallery app, which automatically integrates with your google+/picasa pictures is google's own customisation. I know this because I run CM10.1 on my N7 and had to install googles customised gallery app from gapps to get back the picasa integration there.
EDIT: just found out how to get the gallery app to view my own flickr/picasa pictures, which is cool. After you've gone into "my photos" you might have to change the view/mode of organisation in the top left hand corner from "events" to "albums". I'm not sure why the flickr and picasa pictures don't show up in the events view - the albums on there will have creation dates and all the files have intact exif data - but perhaps it just doesn't integrate online albums in the events view. Either way, when you switch to "albums" you can then pick either picasa or flickr and browse your albums/images on those sites.
