The two applicants for a Greater Boston casino license responded in typical fashion to the Massachusetts Gaming Commission’s proposed licensing conditions, with Mohegan Sun trying its best to please the commissioners and Wynn Resorts taking a much more confrontational tone.

Two top Mohegan officials said in a letter to the commission that they had assented to nearly every condition the commission proposed, added enhancements to others, and even came up with new conditions, all in a bid to make their proposal more acceptable.

By contrast, Steve Wynn, the blunt-talking Las Vegas casino mogul, sent a letter to the commission in which he defended his building design from criticism by one commissioner, rejected traffic mitigation measures pushed by two commissioners, and fired back at the city of Boston for its “irrational demands.”

The letters from Mohegan Sun and Wynn were submitted to the commission on Friday but not released until Monday. Wynn officials on Monday tried to walk back Wynn’s comments on the casino’s design, sending an email to the commission clarifying that Wynn was willing to come up with a new design and in fact had already begun that process.

The jockeying by the two companies was part of a delicate process to win support from the commission. Mohegan Sun took the more conciliatory approach, while Wynn stood its ground for the most part, then backtracked a bit on the design issue.

In his letter to the commissioners, Wynn said he would investigate whether some of the building materials they had raised concerns about would stand up to northeast weather conditions, but he did not appear to be willing to redo the design. “We appreciate the commission’s suggestion and believe the building will have a distinctive presence on the Everett shoreline of the Mystic River,” he said in his letter.

As for criticism from the Massachusetts chapter of the American Institute of Architects that the Wynn proposal did not fit in with its surroundings, Wynn answered with a somewhat sarcastic response. “Perhaps we should have adopted the shape of a fuel storage tank or a big box retailer, notably the surrounding structures of our neighborhood,” he said.

James McHugh, one of the commissioners, said he didn’t think his suggestion of a redesign was an opportunity for Wynn’s humor.

The email sent to the commission Monday morning came from Jacqui Krum, one of the Wynn Resorts attorneys. She said Wynn would explore a redesign of the building. Michael Weaver, a spokesman for Wynn, said the company wanted to clear up any confusion. “We should have been more direct with that,” he said.

Wynn agreed to increase upfront and annual payments to the city of Boston but rejected many of the traffic mitigation measures for Sullivan Square that had been suggested by two of the commissioners. Boston has refused to negotiate with Wynn on mitigation payments, leaving the job up to the commission.

The commissioners said Wynn’s proposal would increase the casino company’s overall payments to Boston from $46 million to $63 million. Some of the commissioners viewed the offer as an attempt to put a finite dollar figure on the traffic mitigation issue rather than working with all the parties to reduce casino traffic moving through the congested square.

Wynn, in his letter, said his company has abided by the commission’s regulations at every turn but been stymied by Boston’s refusal to negotiate. “We were unable to meet the irrational demands of the city of Boston. Further to that point, Boston, ignoring the law and adopting an arbitrary and unreasonable attitude, refused even to engage in the legally mandated procedures. They ignored the deadlines for arbitration and chose instead to snub the process,” he wrote in his letter. “Boston has sought to use the enormous leverage of the license itself to extract from us amounts of money and conditions that are inconsistent with common sense.”

Boston Mayor Marty Walsh last week accused the commission of being biased in favor of Wynn. One of his top aides said in a letter to the commission that the city was within its rights not to negotiate with Wynn because the arbitration process crafted by the commission was illegal. Walsh, however, negotiated a hefty mitigation agreement with Mohegan Sun that would pay the city $20 million a year.

Wynn’s refusal to accept the Sullivan Square traffic mitigation measures proposed by two of the commissioners angered them. A third commissioner suggested imposing the traffic mitigation measures on Wynn as a “take it or leave it” condition of the license. Instead of doing that, or at least before taking that approach, the commissioners asked Wynn and Mohegan Sun to come in on Tuesday and explain their positions on the licensing conditions. How they respond could well determine who wins the license.

Mohegan Sun issued a statement after the meeting asserting that it has approached mitigation in a collaborative manner and come up with “the nation’s largest resort casino mitigation package.” Mohegan Sun said its approach stands “in stark contrast to the approach taken by our competitor.”