Here at Unconsumption, we love cassette-related repurposing; check out our collection of past posts here.
However, this photo shows two products that were designed specifically for iPhones: An iPhone cover that looks like a cassette tape, and a case that fits it.
So, no, this is not an old cassette tape case repurposed as a phone holder.
That said, an iPhone can be placed vertically in an old cassette tape case. Try it — it works well!