HBO Max premiered, and most of the episodes available have full Muppet Wiki guides with images for all the segments. There's only a handful that do not have images yet (two of those now have full pictured guides as a result of being on HBO Max), and only one that doesn't have a full guide yet.
But if you have HBO Max, you can now see the debut of Granny Bird, the opening of Hooper's Store, Bert leaving Ernie, Oscar hiring Cookie Monster to cook for him (one of the ones yet to have all the pictures), a number of sing-along episodes, the entire week of the Puerto Rico trip (including when they returned), the introduction of Elmo's doll Baby David (or did the wiki get those images from a fan recording?), Mr. Hooper allowing his store to be a filming location, Olivia moving to the street, the debut of Alice Snuffleupagus, and visits from James Earl Jones, Sally Ride, and the cast of The Electric Company.
I am thinking the "Elmo's new doll" (#2256) may have been previously uploaded to YouTube or somewhere, or at least just the street scenes. The images were likely screen captures (via pressing the PrintScreen key) from the video. As far as I know, the full episode hasn't been on YouTube or any similar site for a while, but a much better quality broadcast is now on HBO Max.