Product identity and trust
Tester bottle vs retail bottle
Tester and retail bottles can differ in presentation or intended use, but there is no universal rule covering every brand and seller. Verify the exact version, condition and included packaging rather than assuming equivalence.
A HUME Fragrance buying guide

Ask what is included
Confirm cap, box, stated volume and whether the item has been used. Do not infer these from a stock photograph.
Match the fragrance identity
Check maker and version before comparing prices. Tester wording does not establish a stronger or weaker formula.
Check provenance separately
A presentation difference is not an authenticity verdict. Use the brand's own channels to check retailer claims where available.
Try this before you buy
Compare the tester and retail offers using identity, quantity, condition and included presentation as separate fields.