SFMTA installed planters and painted circles at the West Portal station hub over the past few days.
From SFMTA's West Portal Station Safety and Community Space Improvements page:
In addition to beautifying the area, these improvements are designed to discourage people from walking across the rail tracks outside of designated crossing locations.
These changes are the final items being implemented as part of the West Portal Station Safety and Community Space Improvements Project. Later this year, we expect to share a draft evaluation on all project changes with a goal of assessing how closely we are meeting the projects goals.
The planters are large, robust, and exactly the kind of solid objects that should be used routinely to keep drivers out of daylighting zones and other areas that can lead to a collision.

Still to be installed: a bikeshare station and additional paint for the crosswalks.
These treatments are attractive and welcome, but it's essential to remember that this is all that remains of a far larger and more potent safety treatment proposed in the spring of 2024. That came in response to an errant driver who crashed over the curb on Ulloa and killed a family of four that was taking Muni to an outing at the zoo.
The original proposal would have prevented drivers from crossing in front of the station—an ongoing source of train delay and a continued risk for the 50,000 daily Muni riders who alight there.

"Streets Forward's petition calling for that intersection to be closed to car traffic and have Transit-Only Lanes added to West Portal Avenue and Ulloa Street was supported by more than 1,000 people in less than a month after the dangerous design led to the family of four being killed," wrote Streets Forward's Luke Bornheimer, in an email to Streetsblog about the hamstrung installation. "The public overwhelmingly supported that proposal, but the City capitulated to a few people who wanted to maintain the dangerous and unsustainable status quo."

"Mayor London Breed and Supervisor Myrna Melgar announced a watered-down plan for the West Portal safety improvements. This new plan removed five of the eight proposed turn restrictions and about 70 percent of the proposed transit-only lanes in front of the West Portal transit station," wrote the San Francisco Transit Riders during the failed campaign to save the original design.
Melgar, who was up for re-election last November, responded to a handful of outraged motorists who didn't want to be diverted one block. She paused the plan and maneuvered successfully to stop most of the SFMTA's safety and transit improvements.

"This is how, and why, our roadway safety crisis remains out of control," added Bornheimer. "We will never address our roadway safety crisis if every roadway safety or sustainable transportation improvement is abandoned the moment a few people get upset."