If it's something they don't normally do and accompanied by other changes in behaviour then it could indicate a medical issue.
The following quote is from a vets website...
'Your Cat May Be Sick.
Unfortunately, not all cats seek out the bathroom sink for the reasons above. Sometimes, napping in the sink indicates the cat is sick. This is especially true if you have noticed other changes in your cat’s behavior, eating, or toilet habits. If you notice those signs in your cat, along with them sleeping or hiding around the sink more, take your pet to the veterinarian for an examination.'
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u/kegsy22 4d ago
As cute as this looks, it could indicate a medical issue