According to this article it's 10% of the total value of the partner solution. So presumably that's 10% of the total cost of the customer's Teams subscription fees + LiveTiles products implemented.
The wholesale cost to LVT for reselling Teams would obviously be offset by the revenue generated by the customer contract, as LVT would no doubt add a margin to cover any LVT integrations. And perhaps the 10% of total contract value back from Microsoft is done as a discount on the wholesale cost LVT's pays for licensing Teams on their customers behalf.
You'll note in this slide it says "FREE access to Microsoft Teams*", so clearly the customer is not being charged a fee directly from MSFT for Teams. The costs would fall under the subscription fees they pay to LVT.
It should be noted this would only be for direct sales made by LVT's own sales team or from a co-sell referral from MSFT through the program. Any sales made by agents through LVT's reseller network would get that 10% from Microsoft directly. However that just provides an added incentive to those sellers + Microsoft's own global network of sellers to co-sell Teams with LiveTiles solutions included.
LVT Price at posting:
23.0¢ Sentiment: Buy Disclosure: Held