The "masked object fail" is a concept in user experience (UX) design, and while it's not a specific, widely-known incident with a formal name, it's a perfect way to describe a common type of usability problem. It's a failure of a design that "masks" or hides the true nature of an interactive element, leading to user confusion and frustration.

Here's how this concept applies to platforms like Pinterest:

What is Masking in UX Design?
In the context of UX, "masking" occurs when different objects or elements within a user interface appear identical, even though they have distinct functions. This lack of visual distinction makes it difficult for users to understand what each element does, leading to:

Confusion: Users can't tell the difference between a pin, an ad, a video, a product link, and a recommendation.

Diminished Trust: When a user clicks on something that looks like an image but leads them to an unexpected place (like an ad or a purchase page), it erodes their trust in the platform.

Increased Cognitive Load: Users have to spend more time and mental effort deciphering the function of each element, which slows down their Browse experience.

The "Pinterest Fail" and How It Fits the Masked Object Model
Pinterest, with its heavily visual and card-based interface, is particularly susceptible to this kind of UX fail. A pin's primary purpose is to be a visual bookmark, but it can be so much more. This is where the masking happens.

Here are some examples of how Pinterest has been criticized for this type of "trickery":

The Ad vs. Pin Problem: Ads on Pinterest are often designed to look almost identical to regular pins. They use the same card format, the same visual style, and are seamlessly integrated into the feed. A user might click on a beautiful image, expecting to save it to a board, only to be taken to a product page. This masks the ad's true nature as a sponsored post, which can feel deceptive and annoying to the user.

The Video vs. Image Problem: A user might be scrolling through their feed and see what looks like a static image, but when they tap on it, a video starts playing unexpectedly. The visual cues for a video (like a play button or a small duration counter) might be too subtle or non-existent, masking its function. This can be jarring, especially for users Browse in a quiet environment.

The "Pin It" Button Dilemma: In some past iterations, the process of "pinning" an image was convoluted, requiring multiple clicks and sometimes a pop-up to a different screen. The core function of the site—saving an image—was masked by an overly complex user flow, creating frustration for users who expected a simple, one-click action.

The "See It" vs. "Buy It" Problem: A user might find a product they like, but the button to "see it" on the creator's site is visually similar to a button to "buy it" directly. This can create confusion, as the user might not be ready to purchase and is just looking for more information.

In essence, the "masked object fail" on Pinterest is a design anti-pattern where the platform's various functionalities are hidden behind a uniform, visually appealing facade. While this is often done to create a clean, minimalist aesthetic and drive certain user behaviors (like clicking on ads or making purchases), it can backfire by creating a frustrating and untrustworthy user experience.