The phrase "are occasionally shown" is correct and usable in written English.
It can be used when describing something that is displayed or presented from time to time, rather than consistently.
Example: "In the gallery, various artworks are occasionally shown to highlight different themes and styles."
Alternatives: "are sometimes displayed" or "are intermittently presented".
Most of the zoo's mammals are autopsied, and these procedures are occasionally shown to visitors.
She and her turtle sidekick are occasionally shown conversing in English, but otherwise the science seems solid, and the characters never come off as cuddly or anthropomorphized.
In another example, Sam and Max are occasionally shown playing a game called "fizzball", in which the object of the exercise is to hit a can of beer in mid-air with a solid axe handle.
(If anyone in attendance is grumpy, it's Raphael's rival Michelangelo, who is occasionally shown hiding under the bed).
I was in the press room when Best Picture was announced, with about a hundred journalists who had spent the evening watching the ceremony on monitors while the winners were occasionally shown in to answer questions.
We're occasionally shown maps with the angry red rays of the Japanese imperial flag delineating the ever-decreasing reach of the empire but these don't give us a clue to the import of any given victory or loss.
When the series went on the air in 2009, most of the buzz centered on Mitchell and Cam, who were occasionally shown together in bed, cracked jokes at their own expense, and flaunted every stereotype.
We're occasionally shown maps — with the angry red rays of the Japanese imperial flag delineating the ever-decreasing reach of the empire — but these don't give us a clue to the import of any given victory or loss.
Ken has had several forays into journalism for left-wing publications over the years, and was occasionally shown to be frustrated that his political views were not shared by others.
Although only the cedar and Bohemian waxwings normally have red tips on their wing feathers, this feature is occasionally shown by the Japanese waxwing, suggesting that this was originally a whole-family characteristic that has been lost in one species, rather than an indicator of a close relationship.
Aside from the Eds, the other characters in the cul-de-sac, and the Kanker Sisters, no other characters appeared in the series until the fifth season, when the silhouettes of other people were occasionally shown, and in one episode the arms of Eddy's father and Ed's mother were seen.
