Contacts lists everyone who commented, sent a DM or tapped a button: photo, handle, followers, whether they follow you, their latest comment or message and on which post.

Photo and followers
Instagram only shows the photo, name and follower count of people who chatted with you by DM or tapped a button. People who only commented show up with their initial and handle. Since almost everyone who asks for the link ends up in your DMs, most of them get a photo. This info is refreshed once a day.
Tags
falatu adds some tags on its own:
| Tag | When |
|---|---|
| lead | Sent you a DM. |
| asked for link | Commented the word in the last 90 days. |
| big profile | Has 10K followers or more. |
| new follower | Started following you in the last 30 days. |
| complaint | Complained in the last 30 days. |
You can create your own too (up to 30 characters), rename and delete them. Filter by tag in Contacts and in each post's activity. Every contact has a note field so you remember who's who.
Big profiles
Contacts → Big profiles holds the people with 10K+ followers who interacted with you, in tiers: 10K+, 50K+, 100K+ and 1M+. It shows whether they're verified, whether they follow you and what they commented. Know who with a big audience is already paying attention to you.

- Tag partnership adds the "partnership" tag so you can find them later.
- Open conversation takes you to your DM with that person on Instagram.
- Optional: an email when someone with 100K+ interacts (in Settings → Automation defaults → Notify me, off by default).
On the Free plan you see how many big profiles interacted; seeing who they are is part of the Pro plan.