How can I download images on a page using puppeteer?

If you want to skip the manual dom traversal you can write the images to disk directly from the page response.

Example:

const puppeteer = require('puppeteer');
const fs = require('fs');
const path = require('path');

(async () => {
    const browser = await puppeteer.launch();
    const page = await browser.newPage();
    page.on('response', async response => {
        const url = response.url();
        if (response.request().resourceType() === 'image') {
            response.buffer().then(file => {
                const fileName = url.split("https://stackoverflow.com/").pop();
                const filePath = path.resolve(__dirname, fileName);
                const writeStream = fs.createWriteStream(filePath);
                writeStream.write(file);
            });
        }
    });
    await page.goto('https://memeculture69.tumblr.com/');
    await browser.close();
})();

See the documentation for page.on and for the HTTPResponse object that you get from page.on('response', ...).