You can scroll down or tap the "down" button to view each frame on a member's profile. If you like that particular frame, you can tap the "Spark" icon to send them a message or a "Quick reaction" emoji.
For Top 3 frames, select three images which apply to you. If you and the member have all three images in common, you become an instant match.
If you have only 1 or 2 images in common, you will be added to their Visitors section. If that member replies, you will be moved to their Matches section. You cannot send another message until they reply to you.
You can find your chats by tapping the chat icon in the top right-hand corner of the screen. Swipe left or right to switch between matches or visitors.