Is it possible to spoof an IP address to an exact number?

The title says it all really. Say my IP address was and I wanted to change or ‘spoof’ it so that its exactly, would this be possible or are there too many varying factors that need to be taken into account before getting a definitive answer?

Why you might ask?

Well I was in a store the other day and they had iPads around the room setup so that they were showing the store’s online website. I went over and looked at one and noticed that what was showing on their in-store iPads was different to what I would see by simply connecting to their site via my phone (and yes, they were both the exact same link using the same exact browser, Safari).

This lead me to think that the only way they’re able to do this is by either having the site detect the device’s IP address and show specific (or exclusive) content on their homepage based on that, or by having the site detect that the device is using the stores WiFi (although I doubt this is possible, hence why I thought the IP route was more plausible).

So I was curious whether it’d be possible to spoof my device’s IP to that of the stores’ exact IP so that my device showed exactly what theirs did in regards to their website.

Feel free to discuss this, I know this is very very specific and with minimal details known, so I doubt there’s a definitive solution…