This is one of Robert Morningstar's collection of "lunar anomalies" by which he hopes to persuade us that the Moon is the cradle of some ancient civilization. He trotted this out on Richard Hoagland's blogtalk show, with this accompanying text:
"In this, and many other misapplications of Gestalt Psychology, NASA intentionally blinded public perception to hide PROOF of alien activity and construction on the Moon for more than half a century."Morningstar proclaims himself to be "a specialist in photo interpretation, geometric analysis and computer imaging." However, we know from previous articles on this blog that AM*'s photo interpretation skills are a joke (this one, too).
In this case, he's excelled himself by misinterpreting jpg pixellation as the "serrated edges of a construction beam."
His caption says that this is a detail from a Lunar Orbiter 4 image of the satellite crater Deluc L (The crater is named for the Swiss geologist Jean-André Deluc, and has 23 named satellites). However, I don't know where he got that image from, and (typically) he doesn't help us by giving its catalog number. The only Lunar Orbiter 4 image showing Deluc is Frame 4119, Sub-frame h1 (BUT SEE COMMENT #2 FROM ANONYMOUS, BELOW.). Here it is, with some of the satellites identified:
Deluc Main is at 55° S, 2.8° W. Deluc L is at 60.8°S, 6.2° W, and it's just out of this frame to the west of Deluc E. Here's a view from Lunar Reconnaissnce Orbiter centered on Deluc L, with Deluc Main up at top and slightly right of center.note 1
So I can't tell what the "construction beam" actually is (AGAIN SEE COMMENT #2), but it's certain to be one of the many, many imaging artifacts that are all over Lunar Orbiter photography. On that mission, flown in 1967, the photos were developed on board by a semi-wet process, then scanned for transmission. This image of crater Euctemon (76.4°N, 31.3°E), also from AM*'s collection, unquestionably shows a scanning dropout.
In short, these images are not "PROOF of alien activity and construction on the Moon," but "PROOF of Robert Morningstar's incompetence. FURTHER PROOF, I should say.
Thanks to Astroguy for monitoring
 Here's the raw image from the library. Note that a 17MB .tiff is available. If that's not good enough for you, the Lunar Orbiter Image Recovery Project offers a 652 MB download (!)