It will set off the audit alarm bells at the IRS. A home office can be just computer in a spare bedroom, not a place where you meet customers etc.
What IRS reg says that?
You might want to read what the IRS says:
https://www.irs.gov/Businesses/Small-Businesses-&-Self-Employed/Home-Office-Deduction
Look under part 2 of requirements to claim the deduction. Meeting with clients in your home is right there.
The wisdom of taking this deduction would depend a lot on the overall expense versus the amount of income to the business is generating, and what kind of a business it is. For example, any kind of personal service business such as a financial advisor, or career coach etc. that the business could claim need to create a calm soothing environment so that the clients can think clearly with reduced anxiety, would have no problem selling the IRS on the deductibility of her aquarium in the office. It’s no different than a dentist or a doctor’s office. If it’s lumped in with office furniture and decor know is gonna know it’s an aquarium anyway.
How about a bathroom?