Guidelines for images in guides

I couldn't find any documentation on this, but what are the limits on images used in HTML guides? I'm seeing various images used like key art, icons, etc. in addition to standard screenshots, so it seems pretty loose as long as it's relevant.

I ask because I'm working on some guides that I plan to support with screenshots from commentary playthroughs I've recorded. The simplest solution is to grab screenshots as-is, which does contain relevant screenshots from the games but also has the boxshot and my mug in the corner. Now should it be fine to use these images as they are or do you reckon I need to crop them so it's just the screenshots? I'd add a caveat about the source of the images (me) so it's clear to the reader why they're seeing extra stuff.

Example:

https://gamefaqs.gamespot.com/a/user_image/6/4/9/AAZQemAAByap.jpg

In my opinion, as you said: "as long as they are relevant", the layout of supplementary images and their usage really depend on how the author wants to provide the information to the readers. I'll absolutely use image for maps and also for describing complicated stuff, with extra editing such as arrows and numbers if required. However, I'd make sure that the guide is still readable if for somewhat reason all images are not displayed and videos are unplayable. Because they are just "supplementary", as I said above.

A few months ago, instead of writing a guide, I decided to post my "research" in the game's board page. It's a platform game with collecting coins as the optional objective. It's not necessary to collect any number of coins since the next level will be accessible as long as the player reaches the finish line. However, the level's clear percentage is measured by how many coins you've collected in that level; collecting all coins will yield 100% for sure. But the developers won't make it easy since there are secrets and hidden coins all over the levels. At first, I recorded my playthrough and had a plan to capture screenshots (like you are doing now / want to do) to show what I found in the game. But later I figured out that it's simply not enough to clearly show what I wanted to. After writing for a while, I decided to scrap that, make a summary of important points of each level, and then post it in the board. Since you also record videos, you may want to try this type of guide too.

https://gamefaqs.gamespot.com/boards/198253-pandemonium/79334441
https://gamefaqs.gamespot.com/boards/198255-pandemonium-2/79334444

As long as the screenshot is relevant to that portion of the guide. On one hand, if I had done any videos and was featured on my YouTube channel, I may include a link to the video for the readers that could use a bit more visual aid. That's if the video isn't broken down by level and whatnot.

Wouldn't it look neater cropped though?

Yeah... now that I slept on it, I agree. I'm just gonna go through and crop them.

But good idea on the video links for extra assistance, I'll def do that. And thanks for the suggestions, everyone.