If you're looking for a specific group of photos you have filtering options at your disposition.
Press the home icon in the the bottom left corner of your app to access the photo feed. On top of the feed you'll see a banner with different display settings:
By pressing the feed icon represented by two horizontal lines you can scroll through all posts individually.
This is the standard view and is great for taking a closer look at all the amazing details in each photo.
By pressing the grid icon you can view several images at once in a grid-like overview. Click on any image to enhance it so you can take a closer look, like it or share it.
This view is great if you're searching for specific images.
To view all the posts in your browser, click on Gallery in the side menu.
On the following page you can click on the filter- icon and you will see several filter options to choose from.