Slack API: How to add user avatars in message when they click a button?

Question

I think there's something in block kit documentation I haven't read yet, but I'm curious how one could display user avatars in a block like shown in the sample image below? Cheers.

Answer 1

This template is literally available in App Templates of Block Kit Builder

https://api.slack.com/tools/block-kit-builder?template=1
Search for Poll after opening app templates.

For the avatar picture,
You need to use https://api.slack.com/methods/users.info to get image url.
For formatting,
This is the block you are interested in:

{
            "type": "context",
            "elements": [
                {
                    "type": "image",
                    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/profile_1.png",
                    "alt_text": "Michael Scott"
                },
                {
                    "type": "image",
                    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/profile_2.png",
                    "alt_text": "Dwight Schrute"
                },
                {
                    "type": "image",
                    "image_url": "https://api.slack.com/img/blocks/bkb_template_images/profile_3.png",
                    "alt_text": "Pam Beasely"
                },
                {
                    "type": "plain_text",
                    "emoji": true,
                    "text": "3 votes"
                }
            ]
        }

Screenshot