expres terms

Hello Sir
Please explain the main point in the following case of Nicloene v Simmonds

The facts:
The claimant offered to buy steel bars from the defendant. A contract was made by correspondence, in which the defendant provided that ‘the usual conditions of acceptance apply’. The defendant failed to deliver the goods and argued that there had been no explicit agreement.

Decision:
The words should be disregarded. The contract was complete without these words; there were no usual conditions of acceptance
Thanks in advance 🙂