Memory is not one single skill. Remembering a number sequence feels different from remembering locations on a grid. One depends heavily on verbal or numerical recall, while the other depends more on spatial attention.
That is why a visual memory test can be a useful addition to number or sequence challenges. Instead of typing back digits, you need to remember where highlighted items appeared and reproduce the pattern after it disappears.
It also works well as a short break activity. Visual memory tests are active, but they do not require a long time commitment. A few rounds can give you a quick sense of focus before returning to work, study, or gaming.
The key is to compare like with like. Do not treat a visual memory score as the same thing as a number memory score. They measure different task styles, and both can be useful in a broader set of quick cognitive challenges.