Environment:
Browser / Version: Firefox Nightly 201221 (🦎 86.0a1-20201218095607)
Operating System: Samsung Galaxy S8 (Android 9) - 1440 x 2960 pixels, 18.5:9 ratio (~570 ppi density), Huawei P20 Lite (Android 8.0.0) - 1080 x 2280 pixels, 19:9 ratio (~432 ppi density)

Steps to reproduce:

1. Navigate to https://daftsex.com/watch/-186863595_456239208
2. Scroll down the page.
3. Observe the images.

Expected Behavior:
Images load.

Actual Behavior:
Images don't load.

Notes:

1. Screenshot attached.
2. The issue is not reproducible with ETP - Standard enabled.

We have blocked the userapi.com in the strict mode which leads to this issue.

The video plays for me now, opening popups before it plays. Tim, is it working for you now too?

The image is still not loading for me. I think this is the main issue here.

Ah, right, strange that I didn't notice the missing images at first. They're hosted under sun9-36.userapi.com, so the best we could probably offer is to allow users to opt into yellowlisting them somehow. This sounds like a similar case to bug 1706645. I've made a meta-bug about hotlinked userapi.com resources, bug 1707939.