Google announced a new integration for both Google.com and Google+ photos, that lets you find you and your friends Google+ photos directly from Google search. When you are signed in to your Google+ enabled Google Account, then go to Google.com and search your Google+ photos with keyword of [my photos] or [my photos from new york last year] or [matt’s photos of food]. It shows all your Google+ photos related to your keyword.
And also the company starts using computer vision and machine learning to help recognize more general concepts in your photos such as sunsets, food and flowers. So you can filter photos search result in above categories. For example to get flowers photos which is saved in your Google+ account, search [my photos of flowers] then you will see like below image with your Google+ flowers photos
You can also try out this feature on Google+ Photos, currently this feature available in English on Google.com