Tesla (TSLA) - Get Report  laid out a shimmering vision of its business the post- SolarCity (SCTY) acquisition, introducing a solar roofing concept beautiful enough to be a welcome addition to almost any home. Alas, for shareholders the glare of a prominent short-seller outshone the announcement.

CEO Elon Musk unveiled a range of sun-harvesting roofing shingles at an event at Universal Studios in Los Angeles Friday night, part of his grand vision of a household generating its own power via its SolarCity-made roof, storing it in Tesla battery units and then using it on green products like Tesla electric vehicles. Tesla has offered to acquire SolarCity, a company Musk has close ties to, for $2.6 billion as part of the CEO's mission to bring green products to consumers.

The event was seemingly designed to sell the merger as much as it was to sell roof panels, with Musk attempting to answer critics who fear that money-losing SolarCity is an unnecessary distraction -- and cash drain -- for an automaker that is at the same time racing to bring its more affordable Model 3 to the masses by late next year. Shareholders from both companies are expected to vote on the deal on Nov.  17, and with Musk and other key insiders not voting due to potential conflicts the Tesla vote could be close.

But Tesla shareholders were seemingly underwhelmed by the plans, sending shares down more than 1.5%, or $3, to below the psychologically important $200 level on Monday afternoon. While the demonstration roofs were impressive, the presentation was short on key facts, including details on how much the roofing tiles would cost, when they would be available, what other technology was needed and how expensive they would be to install and maintain.

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The presentation, like many events by Tesla, was heavy on hope and long-term vision but short on specifics. It was likely not helpful to Tesla that the demonstration occurred on the same day that noted hedge fund manager David Einhorn criticized the company for just this sort of showmanship.

in a quarterly letter dated Oct. 28, Einhorn, founder of Greenlight Capital, criticized Tesla shareholders for being "willing to look past years of over-promising and under-delivering from a promotional CEO." Einhorn said "Elon Musk's ability to spin a yarn and keep a story going seems to mesmerize his investors, blinding them to the challenges the company is facing."

Indeed, despite Musk's forecast that SolarCity could be breakeven in the near future and that the solar company is an important part of Tesla's overall mission, the deal seemingly adds little other than risk for the near-term. Oppenheimer's Colin Rusch said he believes that Tesla combined with SolarCity would need to raise about $12.5 billion by the end of 2018 if it's to follow through on all of its many promises, and no one at Tesla is arguing that the SolarCity deal is necessary to get the Model 3 out the door or get its autonomous driving system up to speed.

Musk has always played the long game, and to date Tesla has enjoyed a good deal of success focusing on the big picture. Staying with that theme, Friday's solar panel presentation led off with a discussion of current carbon dioxide levels and the impact solar could have on that number over time.

Bringing down pollution levels is a noble goal, but not necessarily one that will produce big profits for Tesla in the years to come. As Einhorn noted, Tesla shareholders so far have been willing to overlook such concerns. Monday's price action begs the question of whether that pattern is beginning to change.